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Energy Express

  • Editor: Christian Seassal
  • Vol. 22, Iss. S3 — May. 5, 2014
  • pp: A961–A972
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Energy transfer in Eu3+ doped scheelites: use as thermographic phosphor

Katrien W. Meert, Vladimir A. Morozov, Artem M. Abakumov, Joke Hadermann, Dirk Poelman, and Philippe F. Smet  »View Author Affiliations


Optics Express, Vol. 22, Issue S3, pp. A961-A972 (2014)
http://dx.doi.org/10.1364/OE.22.00A961


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Abstract

In this paper the luminescence of the scheelite-based CaGd2(1-x)Eu2x(WO4)4 solid solutions is investigated as a function of the Eu content and temperature. All phosphors show intense red luminescence due to the 5D07F2 transition in Eu3+, along with other transitions from the 5D1 and 5D0 excited states. For high Eu3+ concentrations the intensity ratio of the emission originating from the 5D1 and 5D0 levels has a non-conventional temperature dependence, which could be explained by a phonon-assisted cross-relaxation process. It is demonstrated that this intensity ratio can be used as a measure of temperature with high spatial resolution, allowing the use of these scheelites as thermographic phosphor. The main disadvantage of many thermographic phosphors, a decreasing signal for increasing temperature, is absent.

© 2014 Optical Society of America

1. Introduction

Scheelites are A1-□BO4 compounds (A = alkali, alkaline-earth or rare-earth element, B = Mo, W and some other tetrahedrally coordinated cations; □ denotes a cation vacancy) in which broad possibilities of isovalent and heterovalent cation substitutions result in a range of compounds with interesting optical properties, good stability and simple preparation [1

1. L. Qin, Y. Huang, T. Tsuboi, and H. J. Seo, “The red-emitting phosphors of Eu3+ - activated MR2(MoO4)4 (M = Ba, Sr, Ca; R=La3+, Gd3+,Y3+) for light emitting diodes,” Mater. Res. Bull. 47(12), 4498–4502 (2012). [CrossRef]

3

3. B. S. Barros, A. C. de Lima, Z. R. da Silva, D. M. A. Melo, and S. Alves Jr., “Synthesis and photoluminescent behavior of Eu3+-doped alkaline-earth tungstates,” J. Phys. Chem. Solids 73(5), 635–640 (2012). [CrossRef]

]. Upon heterovalent substitution at the A sublattice, the charge balance can be maintained by the introduction of cation vacancies, giving rise to compositions characterized by a (A + A’):(BO4 + B’O4) ratio different from 1:1. This paper describes the temperature dependent luminescence properties of the CaGd2(1-x)Eu2x□(WO4)4 (x = 0 to 1, □ = vacancy) solid solutions and discusses their potential application as a thermographic phosphor.

The technological applications of luminescent materials are very diverse, going from lighting to display and imaging applications [4

4. V. Bachmann, C. Ronda, and A. Meijerink, “Temperature Quenching of Yellow Ce3+ Luminescence in YAG:Ce,” Chem. Mater. 21(10), 2077–2084 (2009). [CrossRef]

10

10. C.-H. Kim, I.-E. Kwon, C.-H. Park, Y.-J. Hwang, H.-S. Bae, B.-Y. Yu, C.-H. Pyun, and G.-Y. Hong, “Phosphors for plasma display panels,” J. Alloy. Comp. 311(1), 33–39 (2000). [CrossRef]

]. In some cases, the luminescence has a very specific temperature dependence, so that it can be used as temperature sensor [11

11. N. Ishiwada, T. Ueda, and T. Yokomori, “Characteristics of rare earth (RE = Eu, Tb, Tm)-doped Y2O3 phosphors for thermometry,” Luminescence 26(6), 381–389 (2011). [CrossRef] [PubMed]

16

16. X. Wang, J. Zheng, Y. Xuan, and X. Yan, “Optical temperature sensing of NaYbF4: Tm3+@SiO2 core-shell micro-particles induced by infrared excitation,” Opt. Express 21(18), 21596–21606 (2013). [CrossRef] [PubMed]

]. This was first mentioned by Neubert in 1937 and the first application dates back to the 1950s, when a phosphor was painted on the wing surfaces of a wind-tunnel model in order to probe the temperature of different parts [17

17. J. P. Feist, A. L. Heyes, and S. Seefelt, “Thermographic phosphor thermometry for film cooling studies in gas turbine combustors,” P. I. Mech. Eng. A – J. Pow. 217, 193–200 (2003).

19

19. P. Neubert, “Device for indicating the temperature distribution of hot bodies,” US Patent no. 2,071.471 (1937).

]. In principle, many different response modes are possible, but the three most important ones are the relative intensities of emission peaks, changes in decay time and shifts in peak position [20

20. M. M. Gentleman, V. Lughi, J. A. Nychka, and D. R. Clarke, “Noncontact Methods for Measuring Thermal Barrier Coating Temperatures,” Int. J. Appl. Ceram. Technol. 3(2), 105–112 (2006). [CrossRef]

22

22. S. M. Borisov, A. S. Vasylevska, C. Krause, and O. S. Wolfbeis, “Composite Luminescent Material for Dual Sensing of Oxygen and Temperature,” Adv. Funct. Mater. 16(12), 1536–1542 (2006). [CrossRef]

]. For the presently investigated scheelites, the focus will be on the fluorescence intensity ratio response mode. Kusama et al. were among the first to discuss this technique for Y2O2S:Eu3+, but the intensity ratios of the Eu3+ transitions were insufficiently dependent on the temperature to allow its use as thermographic phosphor [23

23. H. Kusama, O. J. Sovers, and T. Yoshioka, “Line shift method for phosphor temperature - measurements,” Jpn. J. Appl. Phys. 15(12), 2349–2358 (1976). [CrossRef]

]. Until now, most research focused on Dy3+ or Sm3+ as more suitable thermographic rare earth activators, using the temperature dependence of the intensity ratio of different emission lines [24

24. A. Khalid and K. Kontis, “Thermographic Phosphors for High Temperature Measurements: Principles, Current State of the Art and Recent Applications,” Sensors (Basel Switzerland) 8(9), 5673–5744 (2008). [CrossRef]

28

28. J. P. Feist, A. L. Heyes, and J. R. Nicholls, “Phosphor thermometry in an electron beam physical vapour deposition produced thermal barrier coating doped with dysprosium,” Proc. Inst. Mech. Eng. Part G J. Aerosp. Eng. 215(6), 333–341 (2001). [CrossRef]

]. However, in this paper it will be shown that in the studied scheelite materials, the varying intensity ratio of the emission of the 5D0 and 5D1 energy level of Eu3+ is sensitive enough for use as temperature sensor. The mechanism behind the temperature dependence is explained by a phonon-assisted cross-relaxation process, and not by thermalisation like in most cases [4

4. V. Bachmann, C. Ronda, and A. Meijerink, “Temperature Quenching of Yellow Ce3+ Luminescence in YAG:Ce,” Chem. Mater. 21(10), 2077–2084 (2009). [CrossRef]

]. To demonstrate the feasibility and prospects of the concept, a patterned resistive heater was coated with CaEu2(WO4)4 and illuminated with monochromatic light at 465 nm. The temperature map obtained by using the 5D0 to 5D1 intensity ratio showed high spatial resolution, in addition to an excellent correspondence with the temperature map recorded by more common infrared thermography.

2. Experimental section

Synthesis of the CaGd2(1-x)Eu2x(WO4)4 solid solutions: a solid state reaction of the tungstates CaEu2(WO4)4 and CaGd2(WO4)4 was performed. The CaGd2(WO4)4 and CaEu2(WO4)4 were prepared by heating stoichiometric amounts of CaCO3, WO3, Eu2O3 and Gd2O3 at 823 K for 10 h followed by annealing at 1203 K for 96 h in air. Appropriate amounts of CaEu2(WO4)4 and CaGd2(WO4)4 were mixed to obtain CaGd2(1-x)Eu2x□(WO4)4 and subsequently annealed at 1203 K.

Structure Analysis: The phase purity of the obtained CaGd2(1-x)Eu2x(WO4)4 (x = 0, 0.01, 0.05, 0.1, 0.25, 0.5, 1) solid solutions was checked with X-ray powder diffraction patterns collected on a Thermo ARL X’TRA powder diffractometer (CuKα radiation, λ = 1.5418 Å, Bragg–Brentano geometry, Peltier-cooled CCD detector).

Spectral characterization: Luminescence emission and excitation spectra were obtained with a FS920 spectrometer (Edinburgh Instruments), using a 450W xenon light source, double excitation monochromator and a R928P photomultiplier. All emission and excitation spectra were corrected for the sensitivity of the spectrometer and the intensity of the excitation. Decay times were collected using a pulsed dye laser (λexc = 385 nm) based on optical pumping by a nitrogen laser (λexc = 337 nm, pulse duration < 1ns, 1Hz repetition frequency) in combination with an intensified CCD detector (Andor Instruments) coupled to a 0.5 m monochromator. All measurements were taken at room temperature unless mentioned otherwise, and the temperature dependent measurements were performed using an Oxford Optistat CF cryostat.

Thermometry: The resistive heater was made by depositing a thin Al layer by electron beam evaporation onto a AF45 glass substrate (Präzisions Glas & Optik, 5x5 cm2), through a mask. Some irregularities were introduced in the heater to obtain temperature gradients upon application of a voltage over the outer contacts. Finally, the patterned heater was covered with a thin film of Al2O3 (100nm) by e-beam evaporation as a diffusion barrier. To deposit the thermographic phosphor, 0.06 g of CaEu2(WO4)4 was mixed with 0.18 g of Silres® (Wacker Chemie), painted on the patterned resistive heater and cured for two hours at 200°C. The material was excited with a Melles Griot argon ion laser with an excitation wavelength of 465 nm. The laser spot was expanded to approximately 3 cm in diameter. Photos were taken with a Nikon D3200 digital camera combined with a 535FS10-M52 green filter (Andover Corporation, transmission peak at 537 nm, 10 nm FWHM) or a red interference filter (peak wavelength of 625 nm) for selecting the green and red emission respectively. To obtain the reference temperature plot a FLIR A35sc (48°) infrared camera was used (320 x 256 resolution, temperature range from −40 °C to 550 °C with an accuracy of ± 5 °C).

3. Results and discussion

3.1 Structural characterization

According to the X-ray powder diffraction, the CaGd2(1-x)Eu2x(WO4)4 micron-sized powders are single phase and possess a body-centered monoclinically distorted scheelite-type structure. Upon the Gd/Eu substitution, the lattice parameters vary from a = 5.2313(2)Å, b = 5.2436(2)Å, c = 11.4382(4)Å, γ = 90.600(2)o for x = 0 to a = 5.2365(2)Å, b = 5.2629(2)Å, c = 11.4547(4)Å, γ = 91.152(2)o for x = 1. Besides the reflections from this basic monoclinic unit cell, satellites are visible on the X-ray powder diffraction patterns. These satellites originate from incommensurately modulated ordering of the A cations and vacancies. The detailed analysis of this modulation is out of scope of this article and is discussed elsewhere [29

29. V. A. Morozov, A. Bertha, K. W. Meert, S. Van Rompaey, D. Batuk, G. T. Martinez, S. Van Aert, P. F. Smet, M. V. Raskina, D. Poelman, A. M. Abakumov, and J. Hadermann, “Incommensurate Modulation and Luminescence in the CaGd2(1–x)Eu2x(MoO4)4(1–y)(WO4)4y (0 ≤ x ≤ 1, 0 ≤ y ≤ 1) Red Phosphors,” Chem. Mater. 25(21), 4387–4395 (2013). [CrossRef]

].

3.2 Luminescence emission and excitation spectra

Fig. 2 Concentration dependence of the 5D0 - 7F2 emission intensity in CaGd2(1-x)Eu2x(WO4)4.
In Fig. 2 the dependence of the emission intensity of the 5D07F2 transition on the concentration of Eu3+ in CaGd2(1-x)Eu2x(WO4)4 is illustrated, which can be regarded as a measure for the external quantum efficiency. As can be seen, the intensity reaches a maximum for x = 0.5 and levels off for higher concentrations. Note that the concentration quenching is fairly limited, given the high emission intensity for the fully doped CaEu2(WO4)4.

3.3. Decay measurements

The luminescence lifetime of the emission from the different 5DJ levels was found to be independent of the final level 7FJ’. At 75 K all samples show a similar mono-exponential decay for the 5D0 emission (λexc = 385 nm), with a decay constant of 550 µs (Fig. 3), which is in line with previously reported decay times for similar materials [38

38. Y. Su, L. Li, and G. Li, “Synthesis and Optimum Luminescence of CaWO4-Based Red Phosphors with Codoping of Eu3+ and Na+,” Chem. Mater. 20(19), 6060–6067 (2008). [CrossRef]

40

40. H. Wu, Y. Hu, W. Zhang, F. Kang, N. Li, and G. Ju, “Sol–gel synthesis of Eu3+ incorporated CaMoO4: the enhanced luminescence performance,” J. Sol-Gel Sci. Technol. 62(2), 227–233 (2012). [CrossRef]

]. For low dopant concentration, the decay profile shows almost no temperature dependence in the 75 K to 475 K range. For the highly doped samples, the temperature dependence is much more pronounced. The sample with full Eu substitution (i.e. CaEu2(WO4)4) has a mono-exponential decay profile, but the decay time decreases gradually from 470 µs at low temperature to 230 µs at 475 K.
Fig. 3 Decay of the 5D0 emission of CaGd2(1-x)Eu2x(WO4)4 for x = 0.1,0.5 and 1 at 75K (a) and 475K (b).

For the intermediate case of CaGdEu(WO4)4 the decay starts deviating from a mono-exponential profile upon increasing temperature, and an accurate fit can be obtained by combining the low temperature decay component (τ1 = 550 µs) on the one hand and the changing decay component (τ2 = 550 µs to 230 µs) of CaEu2(WO4)4 at all temperatures on the other hand, in the following way:
I(t)=I1.exp(tτ1)+I2.exp(tτ2)
(1)
The fraction of the temperature dependent component in the decay is then defined by:
f2=I2τ2I1τ1+I2τ2
(2)
and remains constant over the whole temperature range (see Table 1).

Table 1. Decay constant and fraction of the variable decay time component of the 5D0 emission of CaGd2(1-x)Eu2x(WO4)4

table-icon
View This Table

Taking into account the limited size difference of Gd3+(r = 1.053 Å) and Eu3+(r = 1.066 Å), we expect both cations to be uniformly distributed in the crystal. For low Eu concentrations this will result in a relatively large average distance between different Eu ions, leading to a low probability of Eu – Eu energy transfer.

As the Gd3+ ion is optically silent in the visible part of the spectrum, we can consider the Eu3+ ion as an isolated center in the Gd3+ dominated host for these low concentrations. For high Eu concentration, energy transfer is likely to occur between the different europium ions and this is obviously the case for the fully substituted CaEu2(WO4)4. Interestingly, we can consistently fit the thermal behavior of the decay for different dopant concentrations with only two types of Eu ions (i.e. isolated ones and those showing energy transfer), both characterized by their own specific thermal behavior.

3.4 Thermal quenching

Similar to the decay profiles, the temperature dependence of the luminescence is completely different for higher Eu concentrations. The 5D0 emission has similar quenching behavior compared to the samples with low Eu concentration, but for the 5D1 emission a strong absolute increase in intensity is observed for temperatures above room temperature. This is illustrated in Fig. 4(b) for CaEu2(WO4)4. For higher Eu concentration the emission output and the decay profiles show a marked temperature dependence and it is therefore expected that energy transfer mechanisms play a role.

Fig. 5 Decay of the 5D1 emission (λexc = 385 nm) at 75 K and 475 K for CaEu2(WO4)4. The fast decay component remains constant and equals 1.8µs. The slow decay component equals the decay constant of the 5D0 emission at the respective temperatures.
In Fig. 5, the decay of the 5D1 emission of CaEu2(WO4)4 is depicted and apparently it consists of both a temperature independent component of the order of a microsecond and a temperature dependent slow component. The luminescence decay for Eu3+ is commonly much faster for the 5D1 emission than for the 5D0 emission, due to non-radiative depopulation of the higher excited state, e.g. by phonon relaxation or cross-relaxation processes. For higher dopant concentration – and thus for higher probability of energy transfer – the emission from 5D1 is often even not visible at all. Here we observe a fast component in the decay for 5D1 emission with a decay constant of 13 µs for CaGd1.8Eu0.2(WO4)4 and 1.8 µs for CaEu2(WO4)4, which is indeed considerably faster than the 5D0 emission. In addition, an unexpectedly slow component with a decay constant of hundreds of µs is observed as well. By comparing this slow component of the 5D1 emission with the decay of the 5D0 emission at the respective temperatures, a clear correspondence is observed.

The fraction of the slow component (defined by Eq. (2)) in the decay of the 5D1 emission varies from f2 = 0.3 at 75 K to f2 = 0.8 at 475 K. This points to an increased feeding of the 5D1 level from the 5D0 level upon increasing temperature for CaEu2(WO4)4, by an energy transfer process.

The same decay analysis was performed for CaGd1.8Eu0.2(WO4)4 (not shown). Although some transfer from 5D0 to 5D1 indeed occurs for these samples, the contribution is too low to result in a considerable increase of the 5D1 emission beyond the normal decay, which can also be observed in Fig. 4(a).

Both the thermal quenching and the decay profiles point at a concentration dependent cross-relaxation process, rather than a simple thermalisation process where the energy difference to populate the 5D1 level from the 5D0 level is fully covered by phonons. As will be substantiated in §3.5, the increase in the 5D1 emission can be explained by a thermally assisted cross-relaxation process with the involvement of two europium ions initially in the excited 5D0 and the 7F2 state:
(D50)ion2+(F72)ion1+phonons(885cm1)(D51)ion2+(F70)ion1
(3)
Fig. 6 Eu3+ energy level scheme illustrating the phonon-assisted cross-relaxation process.
This process, depicted in Fig. 6, favors the 5D1 emission of ion 2 (green arrow) at the expense of the 5D0 emission (red arrow), due to the transfer of the 7F27F0 energy difference from ion 1 (green dotted arrow). As this is not a resonant process, phonons are still needed to overcome the energy difference between 7F27F0 (1000 cm−1 +/− 100 cm−1) and 5D05D1 (1885 cm−1 +/− 100 cm−1). The energy differences between the 2S + 1LJ manifolds were derived from the emission spectrum. For higher Eu concentrations, this cross-relaxation process is more likely to occur due to a reduced average distance between the Eu ions. Note that a similar temperature dependence was observed for the emission of Eu3+ in GdVO4 by Nikolić et al, where the thermal quenching was explained by thermalisation from the lowest to the highest excited level, leading to a thermal barrier of about 1500cm−1 [41

41. M. G. Nikolić, D. J. Jovanović, and M. D. Dramićanin, “Temperature dependence of emission and lifetime in Eu3+- and Dy3+-doped GdVO4.,” Appl. Opt. 52(8), 1716–1724 (2013). [CrossRef] [PubMed]

]. However this thermalisation cannot account for the observed concentration dependence in our case.

The involvement of the phonons in Eq. (3) explains for the observed temperature dependence. This thermally assisted cross-relaxation should indeed result in a slow component in the decay of the 5D1 emission, comparable with this for the 5D0 emission, as the energy transfer can only occur as long as the 5D0 level remains populated. Note that the same temperature dependency for the decay constant of the 5D0 emission (Table 1) and the slow component in the 5D1 emission (Fig. 5) is found.

3.5 Use of CaEu2(WO4)4 as thermographic phosphor

Fig. 7 a) Ratio (R) of the integrated intensities of the 5D1 to 5D0 emission for CaEu2(WO4)4 and the corresponding Arrhenius plot (inset). b) Calculated relative sensitivity Srel as a function of temperature.
Because of the strongly changing emission characteristics upon increasing temperature for CaEu2(WO4)4, this material is suitable as thermographic phosphor. Figure 7(a) shows the ratio of the 5D1 to 5D0 emission intensity as a function of temperature. The intensities are obtained by integrating over the wavelength ranges 535 to 545 nm (5D1-7F1) and 585 to 600 nm (5D0-7F1) respectively, upon steady state excitation at 395 nm. However, one is not limited to this excitation wavelength and specific 5DJ-7FJ’ transitions, as the cross-relaxation mechanism only depends on the emitting 5DJ levels.

Due to the non-resonant character of the cross-relaxation process, the 5D0 and 5D1 energy levels need to be thermally coupled for the process to occur. In case of thermal coupling, it can be shown that the relative population of both levels can be described by a Boltzmann distribution:
R=I1I0=B.exp(ΔEkT)
(4)
with B depending on the degeneracy, emission cross-section and angular frequency of the respective levels, k the Boltzmann constant, T the absolute temperature and ΔE the energy difference between the involved states [42

42. S. A. Wade, “Temperature measurement using rare earth doped fibre fluorescence,” phD thesis (Victoria University, 1999).

44

44. S. F. León-Luis, J. E. Muñoz-Santiuste, V. Lavín, and U. R. Rodríguez-Mendoza, “Optical pressure and temperature sensor based on the luminescence properties of Nd3+ ion in a gadolinium scandium gallium garnet crystal,” Opt. Express 20(9), 10393–10398 (2012). [CrossRef] [PubMed]

]. The uncertainty of the experimental data in Fig. 7(a) is on the order of a few degrees Celsius. Measurements were found to be reproducible upon consecutive heating cycles and did not lead to degradation of the material. The Arrhenius plot of the ratio R is given in the inset of Fig. 7(a), and the fit was obtained by varying both B and ΔE. The fitted value of 1068 cm−1 for ΔE should be compared with the energy of the phonons needed for the process. This energy is determined by the mismatch between the 7F27F0 (1000 cm−1 +/− 100 cm−1) and 5D0 5D1 (1885 cm−1 +/− 100 cm−1) energy difference. The variation on each energy difference arises from the multiplet splitting of 7F2 and 5D1. This value agrees reasonably well with the fitted value of 1068 cm−1, so the use of the Boltzmann equation is validated.

The one to one correspondence between the data and the fit makes CaEu2(WO4)4 applicable as thermographic phosphor from 300 K to at least 500 K. For a quantitative comparison of thermographic phosphors, the relative sensitivity Srel is the most appropriate parameter and is defined as follows [45

45. E. J. McLaurin, L. R. Bradshaw, and D. R. Gamelin, “Dual-Emitting Nanoscale Temperature Sensors,” Chem. Mater. 25(8), 1283–1292 (2013). [CrossRef]

, 46

46. W. Xu, X. Gao, L. Zheng, Z. Zhang, and W. Cao, “Short-wavelength upconversion emissions in Ho3+/Yb3+ codoped glass ceramic and the optical thermometry behavior,” Opt. Express 20(16), 18127–18137 (2012). [CrossRef] [PubMed]

]:
Srel=1RdRdT=ΔEkT2
(5)
The resulting curve is given in Fig. 7(b). The sensitivity varies from 0.014 K−1 at 300 K to 0.0047 K−1 at 475 K. These values are slightly lower than the relative sensitivities for other Eu3+ doped thermographic materials. For example Eu3+ doped (Y0.75Gd0.25)2O3 has a maximum relative sensitivity of 0.025K−1 [47

47. M. G. Nikolić, V. Lojpur, Ž. Antić, and M. D. Dramićanin, “Thermographic properties of a Eu3+ -doped (Y0.75Gd0.25)2O3 nanophosphor under UV and x-ray excitation,” Phys. Scr. 87(5), 055703 (2013). [CrossRef]

]. On the other hand, the scheelite thermographic phosphor has a much larger temperature operation range compared to most self-referencing materials [48

48. C. D. S. Brites, P. P. Lima, N. J. O. Silva, A. Millán, V. S. Amaral, F. Palacio, and L. D. Carlos, “Thermometry at the nanoscale,” Nanoscale 4(16), 4799–4829 (2012). [CrossRef] [PubMed]

]. Compared to the performance of Dy3+, Sm3+ and Nd3+ doped materials or up-conversion nano-particles, the obtained maximum sensitivity is similar or even higher [27

27. A. L. Heyes and J. P. Feist, “The characterization of Y2O2S:Sm powder as a thermographic phosphor for high temperature applications,” Meas. Sci. Technol. 11(7), 942–947 (2000). [CrossRef]

, 47

47. M. G. Nikolić, V. Lojpur, Ž. Antić, and M. D. Dramićanin, “Thermographic properties of a Eu3+ -doped (Y0.75Gd0.25)2O3 nanophosphor under UV and x-ray excitation,” Phys. Scr. 87(5), 055703 (2013). [CrossRef]

53

53. D. Jaque and F. Vetrone, “Luminescence nanothermometry,” Nanoscale 4(15), 4301–4326 (2012). [CrossRef] [PubMed]

].

Fig. 8 Patterned resistive heater with cross-sections for the vertical and horizontal profile indicated by the black lines (left). Temperature plot of the patterned resistive heater, imaged with the use of the thermographic phosphor (middle) and with an infrared camera (right).
Fig. 9 Horizontal (a) and vertical (b) temperature profiles extracted from the temperature plots in Fig. 8.
To prove its usefulness in thermal imaging, CaEu2(WO4)4 phosphor powder was mixed in a 1:3 weight ratio with SILRES® binder and coated onto a patterned, purposely made resistive heater (Fig. 8) to obtain an inhomogeneous temperature distribution. The device was heated to a maximum local temperature of about 150°C. Then, the coated heater was illuminated with the 465 nm emission of an Ar laser to excite Eu3+ via the 7F0-5D2 transition. In order to map the temperature gradients of the heated surface, pictures were taken with a Nikon D3200 digital reflex camera combined with a green and a red narrow band filter, collecting the relevant fractions of the green 5D1 and the red 5D0 emission separately. Images were read out in the NEF data format, and divided pointwise. Using Eq. (4), a thermal map was obtained (Fig. 8, middle). As a reference, images were made with a thermal imaginginfrared camera (Fig. 8, right). For both types of measurements, a horizontal and a vertical temperature profile was extracted from the corresponding thermal maps (Fig. 9) at the positions indicated on the photograph of the coated heater (Fig. 8, left). It can be seen that the thermographic scheelite phosphor is capable of reproducing the temperature gradients in a very accurate way, which proves the applicability of the material in the postulated temperature range.

A major advantage specific for this response mode is that there is no need for an absolute intensity measurement, eliminating errors introduced by fluctuations in excitation intensity and light collection efficiency [45

45. E. J. McLaurin, L. R. Bradshaw, and D. R. Gamelin, “Dual-Emitting Nanoscale Temperature Sensors,” Chem. Mater. 25(8), 1283–1292 (2013). [CrossRef]

]. Together with the obtained high spatial resolution and the non-destructiveness of the method, this makes the material a very promising candidate for thermometry. Indeed, after use, the phosphor coating can be easily removed using an appropriate solvent such as acetone. In addition, the involved emission peaks are very well separated, making the detection relatively easy. The main drawback for the material is the low 5D1 emission intensity compared to the 5D0 emission intensity. Nevertheless, the cross-relaxation process can still be optimized, for example by minimizing the defects in the host material. This reduces the non-radiative decay paths from 5D0 to 7FJ, which can then increase the probability of populating the 5D1 level. In addition, other host materials could be chosen with a different distance between the europium ions or with phonon energies having an improved match with the energy needed for the cross-relaxation process.

4. Conclusion

In this work, we investigated the temperature dependence of both the luminescence and the decay pathways of CaGd2(1-x)Eu2x(WO4)4 scheelites in a systematic way. All phosphors emit intense red light dominated by the 5D07F2 transition at 612 nm, and have similar excitation and emission spectra. The temperature dependence of the 5DJ emission intensities was however found to be strongly dependent on the europium concentration. For high Eu concentration strong cross-relaxation occurred upon increasing temperature due to energy transfer between nearby Eu ions. This thermally assisted cross-relaxation manifests itself in an increasing emission from the 5D1 level, characterized by the same decay time as the 5D0 emission, upon increasing temperature. Because of this specific temperature dependence, CaEu2(WO4)4 was proven to be suitable for intensity ratio based temperature measurements. The ratio of the 5D1 to 5D0 emission intensity follows a Boltzmann distribution equation. Consequently, an accurate estimate of the temperature can be made in the range from 300 K to at least 500 K by measuring the relative emission intensity of both peaks. This temperature range is large compared to other ratiometric systems and it was experimentally shown that the phosphor was able to reproduce temperature gradients with high accuracy and spatial resolution, confirming the applicability of the material for thermometry and thermography. A disadvantage of the present phosphor is the relatively low integrated emission intensity from the 5D1 emission compared to the dominating 5D0 emission, which lengthens the acquisition time for the thermal imaging. Future work will therefore focus on the optimization of the cross-relaxation process and the total emission intensity of the 5D1 state, by optimizing the host composition and reduction of the non-radiative decay paths.

Acknowledgment

This research was supported by FWO (projects G039211N, G006410), Research Foundation - Flanders. V.M. is grateful for financial support of the Russian Foundation for Basic Research (Grants 08-03-00593, 11-03-01164, and 12-03-00124). We gratefully thank Mathias Helsen and Jonas Botterman for assisting in the measurements.

References and links

1.

L. Qin, Y. Huang, T. Tsuboi, and H. J. Seo, “The red-emitting phosphors of Eu3+ - activated MR2(MoO4)4 (M = Ba, Sr, Ca; R=La3+, Gd3+,Y3+) for light emitting diodes,” Mater. Res. Bull. 47(12), 4498–4502 (2012). [CrossRef]

2.

M. M. Haque and D.-K. Kim, “Luminescent properties of Eu3+ activated MLa2(MoO4)4 based (M = Ba, Sr and Ca) novel red-emitting phosphors,” Mater. Lett. 63(9-10), 793–796 (2009). [CrossRef]

3.

B. S. Barros, A. C. de Lima, Z. R. da Silva, D. M. A. Melo, and S. Alves Jr., “Synthesis and photoluminescent behavior of Eu3+-doped alkaline-earth tungstates,” J. Phys. Chem. Solids 73(5), 635–640 (2012). [CrossRef]

4.

V. Bachmann, C. Ronda, and A. Meijerink, “Temperature Quenching of Yellow Ce3+ Luminescence in YAG:Ce,” Chem. Mater. 21(10), 2077–2084 (2009). [CrossRef]

5.

W. B. Im, N. George, J. Kurzman, S. Brinkley, A. Mikhailovsky, J. Hu, B. F. Chmelka, S. P. DenBaars, and R. Seshadri, “Efficient and Color-Tunable Oxyfluoride Solid Solution Phosphors for Solid-State White Lighting,” Adv. Mater. 23(20), 2300–2305 (2011). [CrossRef] [PubMed]

6.

Y. Yang, Q. Zhao, W. Feng, and F. Li, “Luminescent Chemodosimeters for Bioimaging,” Chem. Rev. 113(1), 192–270 (2013). [CrossRef] [PubMed]

7.

K. Uheda, N. Hirosaki, Y. Yamamoto, A. Naito, T. Nakajima, and H. Yamamoto, “Luminescence Properties of a Red Phosphor, CaAlSiN3 : Eu2+, for White Light-Emitting Diodes,” J. Electrochem. Soc. 9, H22–H25 (2006).

8.

X. Zhang, F. Meng, H. Li, and H. J. Seo, “Synthesis and luminescence of Eu3+-activated molybdates with scheelite-type structure,” Phys. Status Solidi 210, 1866–1870 (2013).

9.

P. Benalloul, C. Barthou, and J. Benoit, “SrGa2S4: RE phosphors for full colour electroluminescent displays,” J. Alloy. Comp. 275–277, 709–715 (1998). [CrossRef]

10.

C.-H. Kim, I.-E. Kwon, C.-H. Park, Y.-J. Hwang, H.-S. Bae, B.-Y. Yu, C.-H. Pyun, and G.-Y. Hong, “Phosphors for plasma display panels,” J. Alloy. Comp. 311(1), 33–39 (2000). [CrossRef]

11.

N. Ishiwada, T. Ueda, and T. Yokomori, “Characteristics of rare earth (RE = Eu, Tb, Tm)-doped Y2O3 phosphors for thermometry,” Luminescence 26(6), 381–389 (2011). [CrossRef] [PubMed]

12.

M. D. Chambers, P. A. Rousseve, and D. R. Clarke, “Decay pathway and high-temperature luminescence of Eu3+ in Ca2Gd8Si6O26,” J. Lumin. 129(3), 263–269 (2009). [CrossRef]

13.

Y. Cui, H. Xu, Y. Yue, Z. Guo, J. Yu, Z. Chen, J. Gao, Y. Yang, G. Qian, and B. Chen, “A Luminescent Mixed-Lanthanide Metal-Organic Framework Thermometer,” J. Am. Chem. Soc. 134(9), 3979–3982 (2012). [CrossRef] [PubMed]

14.

A. E. Albers, E. M. Chan, P. M. McBride, C. M. Ajo-Franklin, B. E. Cohen, and B. A. Helms, “Dual-Emitting Quantum Dot/Quantum Rod-Based Nanothermometers with Enhanced Response and Sensitivity in Live Cells,” J. Am. Chem. Soc. 134(23), 9565–9568 (2012). [CrossRef] [PubMed]

15.

B. Lai, L. Feng, J. Wang, and Q. Su, “Optical transition and upconversion luminescence in Er3+ doped and Er3+–Yb3+ co-doped fluorophosphate glasses,” Opt. Mater. 32(9), 1154–1160 (2010). [CrossRef]

16.

X. Wang, J. Zheng, Y. Xuan, and X. Yan, “Optical temperature sensing of NaYbF4: Tm3+@SiO2 core-shell micro-particles induced by infrared excitation,” Opt. Express 21(18), 21596–21606 (2013). [CrossRef] [PubMed]

17.

J. P. Feist, A. L. Heyes, and S. Seefelt, “Thermographic phosphor thermometry for film cooling studies in gas turbine combustors,” P. I. Mech. Eng. A – J. Pow. 217, 193–200 (2003).

18.

L. C. Bradley, “A Temperature-Sensitive Phosphor Used to Measure Surface Temperatures in Aerodynamics,” Rev. Sci. Instrum. 24(3), 219–220 (1953). [CrossRef]

19.

P. Neubert, “Device for indicating the temperature distribution of hot bodies,” US Patent no. 2,071.471 (1937).

20.

M. M. Gentleman, V. Lughi, J. A. Nychka, and D. R. Clarke, “Noncontact Methods for Measuring Thermal Barrier Coating Temperatures,” Int. J. Appl. Ceram. Technol. 3(2), 105–112 (2006). [CrossRef]

21.

H. Peng, M. I. J. Stich, J. Yu, L. N. Sun, L. H. Fischer, and O. S. Wolfbeis, “Luminescent Europium(III) Nanoparticles for Sensing and Imaging of Temperature in the Physiological Range,” Adv. Mater. 22(6), 716–719 (2010). [CrossRef] [PubMed]

22.

S. M. Borisov, A. S. Vasylevska, C. Krause, and O. S. Wolfbeis, “Composite Luminescent Material for Dual Sensing of Oxygen and Temperature,” Adv. Funct. Mater. 16(12), 1536–1542 (2006). [CrossRef]

23.

H. Kusama, O. J. Sovers, and T. Yoshioka, “Line shift method for phosphor temperature - measurements,” Jpn. J. Appl. Phys. 15(12), 2349–2358 (1976). [CrossRef]

24.

A. Khalid and K. Kontis, “Thermographic Phosphors for High Temperature Measurements: Principles, Current State of the Art and Recent Applications,” Sensors (Basel Switzerland) 8(9), 5673–5744 (2008). [CrossRef]

25.

J. Brübach, C. Pflitsch, A. Dreizler, and B. Atakan, “On surface temperature measurements with thermographic phosphors: A review,” Prog. Energ. Combust. 39(1), 37–60 (2013). [CrossRef]

26.

M. G. Nikolic, D. J. Jovanovic, V. Dordevic, Z. Antic, R. M. Krsmanovic, and M. D. Dramicanin, “Thermographic properties of Sm3+- doped GdVO4 phosphor,” Phys. Scr. T 149, 1–4 (2012).

27.

A. L. Heyes and J. P. Feist, “The characterization of Y2O2S:Sm powder as a thermographic phosphor for high temperature applications,” Meas. Sci. Technol. 11(7), 942–947 (2000). [CrossRef]

28.

J. P. Feist, A. L. Heyes, and J. R. Nicholls, “Phosphor thermometry in an electron beam physical vapour deposition produced thermal barrier coating doped with dysprosium,” Proc. Inst. Mech. Eng. Part G J. Aerosp. Eng. 215(6), 333–341 (2001). [CrossRef]

29.

V. A. Morozov, A. Bertha, K. W. Meert, S. Van Rompaey, D. Batuk, G. T. Martinez, S. Van Aert, P. F. Smet, M. V. Raskina, D. Poelman, A. M. Abakumov, and J. Hadermann, “Incommensurate Modulation and Luminescence in the CaGd2(1–x)Eu2x(MoO4)4(1–y)(WO4)4y (0 ≤ x ≤ 1, 0 ≤ y ≤ 1) Red Phosphors,” Chem. Mater. 25(21), 4387–4395 (2013). [CrossRef]

30.

W. Zhang, J. Long, A. Fan, and J. Li, “Effect of replacement of Ca by Ln (Ln = Y, Gd) on the structural and luminescence properties of CaWO4:Eu3+ red phosphors prepared via co-precipitation,” Mater. Res. Bull. 47(11), 3479–3483 (2012). [CrossRef]

31.

G. Blasse and B. C. Grabmaier, Luminescent Materials (Springer - Verlag, 1994).

32.

S. K. Shi, X. R. Liu, J. Gao, and J. Zhou, “Spectroscopic properties and intense red-light emission of (Ca, Eu,M)WO4 (M = Mg, Zn, Li),” Spectroc. Acta Pt. A-Molec. Biomolec. Spectr. 69(2), 396–399 (2008). [CrossRef]

33.

G. Blasse, “The luminescence of closed-shell transition-metal complexes. New developments,” in Luminescence and Energy Transfer (Springer Berlin Heidelberg, 1980), pp. 1–41.

34.

S. Alahraché, K. Al Saghir, S. Chenu, E. Véron, D. De Sousa Meneses, A. I. Becerro, M. Ocaña, F. Moretti, G. Patton, C. Dujardin, F. Cussó, J.-P. Guin, M. Nivard, J.-C. Sangleboeuf, G. Matzen, and M. Allix, “Perfectly transparent Sr3Al2O6 polycrystalline ceramic elaborated from glass crystallization,” Chem. Mater. 25(20), 4017–4024 (2013). [CrossRef]

35.

P. A. Tanner, “Some misconceptions concerning the electronic spectra of tri-positive europium and cerium,” Chem. Soc. Rev. 42(12), 5090–5101 (2013). [CrossRef] [PubMed]

36.

G. Blasse, A. Bril, and W. C. Nieuwpoort, “On the Eu3+ fluorescence in mixed metal oxides. Part I - The crystal structure sensitivity of the intensity ratio of electric and magnetic dipole emission,” J. Phys. Chem. Solids 27(10), 1587–1592 (1966). [CrossRef]

37.

K. Binnemans, “Lanthanide-based luminescent hybrid materials,” Chem. Rev. 109(9), 4283–4374 (2009). [CrossRef] [PubMed]

38.

Y. Su, L. Li, and G. Li, “Synthesis and Optimum Luminescence of CaWO4-Based Red Phosphors with Codoping of Eu3+ and Na+,” Chem. Mater. 20(19), 6060–6067 (2008). [CrossRef]

39.

J. Liao, H. You, B. Qiu, H.-R. Wen, R. Hong, W. You, and Z. Xie, “Photoluminescence properties of NaGd(WO4)2:Eu3+ nanocrystalline prepared by hydrothermal method,” Curr. Appl. Phys. 11(3), 503–507 (2011). [CrossRef]

40.

H. Wu, Y. Hu, W. Zhang, F. Kang, N. Li, and G. Ju, “Sol–gel synthesis of Eu3+ incorporated CaMoO4: the enhanced luminescence performance,” J. Sol-Gel Sci. Technol. 62(2), 227–233 (2012). [CrossRef]

41.

M. G. Nikolić, D. J. Jovanović, and M. D. Dramićanin, “Temperature dependence of emission and lifetime in Eu3+- and Dy3+-doped GdVO4.,” Appl. Opt. 52(8), 1716–1724 (2013). [CrossRef] [PubMed]

42.

S. A. Wade, “Temperature measurement using rare earth doped fibre fluorescence,” phD thesis (Victoria University, 1999).

43.

J. A. Capobianco, P. Kabro, F. S. Ermeneux, R. Moncorge, M. Bettinelli, and E. Cavalli, “Optical spectroscopy, fluorescence dynamics and crystal-field analysis of Er3+ in YVO4,” Chem. Phys. 214(2-3), 329–340 (1997). [CrossRef]

44.

S. F. León-Luis, J. E. Muñoz-Santiuste, V. Lavín, and U. R. Rodríguez-Mendoza, “Optical pressure and temperature sensor based on the luminescence properties of Nd3+ ion in a gadolinium scandium gallium garnet crystal,” Opt. Express 20(9), 10393–10398 (2012). [CrossRef] [PubMed]

45.

E. J. McLaurin, L. R. Bradshaw, and D. R. Gamelin, “Dual-Emitting Nanoscale Temperature Sensors,” Chem. Mater. 25(8), 1283–1292 (2013). [CrossRef]

46.

W. Xu, X. Gao, L. Zheng, Z. Zhang, and W. Cao, “Short-wavelength upconversion emissions in Ho3+/Yb3+ codoped glass ceramic and the optical thermometry behavior,” Opt. Express 20(16), 18127–18137 (2012). [CrossRef] [PubMed]

47.

M. G. Nikolić, V. Lojpur, Ž. Antić, and M. D. Dramićanin, “Thermographic properties of a Eu3+ -doped (Y0.75Gd0.25)2O3 nanophosphor under UV and x-ray excitation,” Phys. Scr. 87(5), 055703 (2013). [CrossRef]

48.

C. D. S. Brites, P. P. Lima, N. J. O. Silva, A. Millán, V. S. Amaral, F. Palacio, and L. D. Carlos, “Thermometry at the nanoscale,” Nanoscale 4(16), 4799–4829 (2012). [CrossRef] [PubMed]

49.

S. A. Wade, S. F. Collins, and G. W. Baxter, “Fluorescence intensity ratio technique for optical fiber point temperature sensing,” J. Appl. Phys. 94(8), 4743–4756 (2003). [CrossRef]

50.

C. Eckert, C. Pflitsch, and B. Atakan, “Sol–gel deposition of multiply doped thermographic phosphor coatings Al2O3:(Cr3+, M3+) (M = Dy, Tm) for wide range surface temperature measurement application,” Prog. Org. Coat. 67(2), 116–119 (2010). [CrossRef]

51.

Z. Boruc, M. Kaczkan, B. Fetlinski, S. Turczynski, and M. Malinowski, “Blue emissions in Dy3+ doped Y4Al2O9 crystals for temperature sensing,” Opt. Lett. 37(24), 5214–5216 (2012). [CrossRef] [PubMed]

52.

P. Haro-González, I. R. Martín, L. L. Martín, S. F. León-Luis, C. Pérez-Rodríguez, and V. Lavín, “Characterization of Er3+ and Nd3+ doped Strontium Barium Niobate glass ceramic as temperature sensors,” Opt. Mater. 33(5), 742–745 (2011). [CrossRef]

53.

D. Jaque and F. Vetrone, “Luminescence nanothermometry,” Nanoscale 4(15), 4301–4326 (2012). [CrossRef] [PubMed]

OCIS Codes
(160.2540) Materials : Fluorescent and luminescent materials
(280.4788) Remote sensing and sensors : Optical sensing and sensors
(280.6780) Remote sensing and sensors : Temperature

ToC Category:
Fluorescent and Luminescent Materials

History
Original Manuscript: February 19, 2014
Revised Manuscript: April 7, 2014
Manuscript Accepted: April 7, 2014
Published: April 22, 2014

Citation
Katrien W. Meert, Vladimir A. Morozov, Artem M. Abakumov, Joke Hadermann, Dirk Poelman, and Philippe F. Smet, "Energy transfer in Eu3+ doped scheelites: use as thermographic phosphor," Opt. Express 22, A961-A972 (2014)
http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-22-S3-A961


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References

  1. L. Qin, Y. Huang, T. Tsuboi, and H. J. Seo, “The red-emitting phosphors of Eu3+ - activated MR2(MoO4)4 (M = Ba, Sr, Ca; R=La3+, Gd3+,Y3+) for light emitting diodes,” Mater. Res. Bull.47(12), 4498–4502 (2012). [CrossRef]
  2. M. M. Haque and D.-K. Kim, “Luminescent properties of Eu3+ activated MLa2(MoO4)4 based (M = Ba, Sr and Ca) novel red-emitting phosphors,” Mater. Lett.63(9-10), 793–796 (2009). [CrossRef]
  3. B. S. Barros, A. C. de Lima, Z. R. da Silva, D. M. A. Melo, and S. Alves., “Synthesis and photoluminescent behavior of Eu3+-doped alkaline-earth tungstates,” J. Phys. Chem. Solids73(5), 635–640 (2012). [CrossRef]
  4. V. Bachmann, C. Ronda, and A. Meijerink, “Temperature Quenching of Yellow Ce3+ Luminescence in YAG:Ce,” Chem. Mater.21(10), 2077–2084 (2009). [CrossRef]
  5. W. B. Im, N. George, J. Kurzman, S. Brinkley, A. Mikhailovsky, J. Hu, B. F. Chmelka, S. P. DenBaars, and R. Seshadri, “Efficient and Color-Tunable Oxyfluoride Solid Solution Phosphors for Solid-State White Lighting,” Adv. Mater.23(20), 2300–2305 (2011). [CrossRef] [PubMed]
  6. Y. Yang, Q. Zhao, W. Feng, and F. Li, “Luminescent Chemodosimeters for Bioimaging,” Chem. Rev.113(1), 192–270 (2013). [CrossRef] [PubMed]
  7. K. Uheda, N. Hirosaki, Y. Yamamoto, A. Naito, T. Nakajima, and H. Yamamoto, “Luminescence Properties of a Red Phosphor, CaAlSiN3 : Eu2+, for White Light-Emitting Diodes,” J. Electrochem. Soc.9, H22–H25 (2006).
  8. X. Zhang, F. Meng, H. Li, and H. J. Seo, “Synthesis and luminescence of Eu3+-activated molybdates with scheelite-type structure,” Phys. Status Solidi210, 1866–1870 (2013).
  9. P. Benalloul, C. Barthou, and J. Benoit, “SrGa2S4: RE phosphors for full colour electroluminescent displays,” J. Alloy. Comp.275–277, 709–715 (1998). [CrossRef]
  10. C.-H. Kim, I.-E. Kwon, C.-H. Park, Y.-J. Hwang, H.-S. Bae, B.-Y. Yu, C.-H. Pyun, and G.-Y. Hong, “Phosphors for plasma display panels,” J. Alloy. Comp.311(1), 33–39 (2000). [CrossRef]
  11. N. Ishiwada, T. Ueda, and T. Yokomori, “Characteristics of rare earth (RE = Eu, Tb, Tm)-doped Y2O3 phosphors for thermometry,” Luminescence26(6), 381–389 (2011). [CrossRef] [PubMed]
  12. M. D. Chambers, P. A. Rousseve, and D. R. Clarke, “Decay pathway and high-temperature luminescence of Eu3+ in Ca2Gd8Si6O26,” J. Lumin.129(3), 263–269 (2009). [CrossRef]
  13. Y. Cui, H. Xu, Y. Yue, Z. Guo, J. Yu, Z. Chen, J. Gao, Y. Yang, G. Qian, and B. Chen, “A Luminescent Mixed-Lanthanide Metal-Organic Framework Thermometer,” J. Am. Chem. Soc.134(9), 3979–3982 (2012). [CrossRef] [PubMed]
  14. A. E. Albers, E. M. Chan, P. M. McBride, C. M. Ajo-Franklin, B. E. Cohen, and B. A. Helms, “Dual-Emitting Quantum Dot/Quantum Rod-Based Nanothermometers with Enhanced Response and Sensitivity in Live Cells,” J. Am. Chem. Soc.134(23), 9565–9568 (2012). [CrossRef] [PubMed]
  15. B. Lai, L. Feng, J. Wang, and Q. Su, “Optical transition and upconversion luminescence in Er3+ doped and Er3+–Yb3+ co-doped fluorophosphate glasses,” Opt. Mater.32(9), 1154–1160 (2010). [CrossRef]
  16. X. Wang, J. Zheng, Y. Xuan, and X. Yan, “Optical temperature sensing of NaYbF4: Tm3+@SiO2 core-shell micro-particles induced by infrared excitation,” Opt. Express21(18), 21596–21606 (2013). [CrossRef] [PubMed]
  17. J. P. Feist, A. L. Heyes, and S. Seefelt, “Thermographic phosphor thermometry for film cooling studies in gas turbine combustors,” P. I. Mech. Eng. A – J. Pow.217, 193–200 (2003).
  18. L. C. Bradley, “A Temperature-Sensitive Phosphor Used to Measure Surface Temperatures in Aerodynamics,” Rev. Sci. Instrum.24(3), 219–220 (1953). [CrossRef]
  19. P. Neubert, “Device for indicating the temperature distribution of hot bodies,” US Patent no. 2,071.471 (1937).
  20. M. M. Gentleman, V. Lughi, J. A. Nychka, and D. R. Clarke, “Noncontact Methods for Measuring Thermal Barrier Coating Temperatures,” Int. J. Appl. Ceram. Technol.3(2), 105–112 (2006). [CrossRef]
  21. H. Peng, M. I. J. Stich, J. Yu, L. N. Sun, L. H. Fischer, and O. S. Wolfbeis, “Luminescent Europium(III) Nanoparticles for Sensing and Imaging of Temperature in the Physiological Range,” Adv. Mater.22(6), 716–719 (2010). [CrossRef] [PubMed]
  22. S. M. Borisov, A. S. Vasylevska, C. Krause, and O. S. Wolfbeis, “Composite Luminescent Material for Dual Sensing of Oxygen and Temperature,” Adv. Funct. Mater.16(12), 1536–1542 (2006). [CrossRef]
  23. H. Kusama, O. J. Sovers, and T. Yoshioka, “Line shift method for phosphor temperature - measurements,” Jpn. J. Appl. Phys.15(12), 2349–2358 (1976). [CrossRef]
  24. A. Khalid and K. Kontis, “Thermographic Phosphors for High Temperature Measurements: Principles, Current State of the Art and Recent Applications,” Sensors (Basel Switzerland)8(9), 5673–5744 (2008). [CrossRef]
  25. J. Brübach, C. Pflitsch, A. Dreizler, and B. Atakan, “On surface temperature measurements with thermographic phosphors: A review,” Prog. Energ. Combust.39(1), 37–60 (2013). [CrossRef]
  26. M. G. Nikolic, D. J. Jovanovic, V. Dordevic, Z. Antic, R. M. Krsmanovic, and M. D. Dramicanin, “Thermographic properties of Sm3+- doped GdVO4 phosphor,” Phys. Scr. T149, 1–4 (2012).
  27. A. L. Heyes and J. P. Feist, “The characterization of Y2O2S:Sm powder as a thermographic phosphor for high temperature applications,” Meas. Sci. Technol.11(7), 942–947 (2000). [CrossRef]
  28. J. P. Feist, A. L. Heyes, and J. R. Nicholls, “Phosphor thermometry in an electron beam physical vapour deposition produced thermal barrier coating doped with dysprosium,” Proc. Inst. Mech. Eng. Part G J. Aerosp. Eng.215(6), 333–341 (2001). [CrossRef]
  29. V. A. Morozov, A. Bertha, K. W. Meert, S. Van Rompaey, D. Batuk, G. T. Martinez, S. Van Aert, P. F. Smet, M. V. Raskina, D. Poelman, A. M. Abakumov, and J. Hadermann, “Incommensurate Modulation and Luminescence in the CaGd2(1–x)Eu2x(MoO4)4(1–y)(WO4)4y (0 ≤ x ≤ 1, 0 ≤ y ≤ 1) Red Phosphors,” Chem. Mater.25(21), 4387–4395 (2013). [CrossRef]
  30. W. Zhang, J. Long, A. Fan, and J. Li, “Effect of replacement of Ca by Ln (Ln = Y, Gd) on the structural and luminescence properties of CaWO4:Eu3+ red phosphors prepared via co-precipitation,” Mater. Res. Bull.47(11), 3479–3483 (2012). [CrossRef]
  31. G. Blasse and B. C. Grabmaier, Luminescent Materials (Springer - Verlag, 1994).
  32. S. K. Shi, X. R. Liu, J. Gao, and J. Zhou, “Spectroscopic properties and intense red-light emission of (Ca, Eu,M)WO4 (M = Mg, Zn, Li),” Spectroc. Acta Pt. A-Molec. Biomolec. Spectr.69(2), 396–399 (2008). [CrossRef]
  33. G. Blasse, “The luminescence of closed-shell transition-metal complexes. New developments,” in Luminescence and Energy Transfer (Springer Berlin Heidelberg, 1980), pp. 1–41.
  34. S. Alahraché, K. Al Saghir, S. Chenu, E. Véron, D. De Sousa Meneses, A. I. Becerro, M. Ocaña, F. Moretti, G. Patton, C. Dujardin, F. Cussó, J.-P. Guin, M. Nivard, J.-C. Sangleboeuf, G. Matzen, and M. Allix, “Perfectly transparent Sr3Al2O6 polycrystalline ceramic elaborated from glass crystallization,” Chem. Mater.25(20), 4017–4024 (2013). [CrossRef]
  35. P. A. Tanner, “Some misconceptions concerning the electronic spectra of tri-positive europium and cerium,” Chem. Soc. Rev.42(12), 5090–5101 (2013). [CrossRef] [PubMed]
  36. G. Blasse, A. Bril, and W. C. Nieuwpoort, “On the Eu3+ fluorescence in mixed metal oxides. Part I - The crystal structure sensitivity of the intensity ratio of electric and magnetic dipole emission,” J. Phys. Chem. Solids27(10), 1587–1592 (1966). [CrossRef]
  37. K. Binnemans, “Lanthanide-based luminescent hybrid materials,” Chem. Rev.109(9), 4283–4374 (2009). [CrossRef] [PubMed]
  38. Y. Su, L. Li, and G. Li, “Synthesis and Optimum Luminescence of CaWO4-Based Red Phosphors with Codoping of Eu3+ and Na+,” Chem. Mater.20(19), 6060–6067 (2008). [CrossRef]
  39. J. Liao, H. You, B. Qiu, H.-R. Wen, R. Hong, W. You, and Z. Xie, “Photoluminescence properties of NaGd(WO4)2:Eu3+ nanocrystalline prepared by hydrothermal method,” Curr. Appl. Phys.11(3), 503–507 (2011). [CrossRef]
  40. H. Wu, Y. Hu, W. Zhang, F. Kang, N. Li, and G. Ju, “Sol–gel synthesis of Eu3+ incorporated CaMoO4: the enhanced luminescence performance,” J. Sol-Gel Sci. Technol.62(2), 227–233 (2012). [CrossRef]
  41. M. G. Nikolić, D. J. Jovanović, and M. D. Dramićanin, “Temperature dependence of emission and lifetime in Eu3+- and Dy3+-doped GdVO4.,” Appl. Opt.52(8), 1716–1724 (2013). [CrossRef] [PubMed]
  42. S. A. Wade, “Temperature measurement using rare earth doped fibre fluorescence,” phD thesis (Victoria University, 1999).
  43. J. A. Capobianco, P. Kabro, F. S. Ermeneux, R. Moncorge, M. Bettinelli, and E. Cavalli, “Optical spectroscopy, fluorescence dynamics and crystal-field analysis of Er3+ in YVO4,” Chem. Phys.214(2-3), 329–340 (1997). [CrossRef]
  44. S. F. León-Luis, J. E. Muñoz-Santiuste, V. Lavín, and U. R. Rodríguez-Mendoza, “Optical pressure and temperature sensor based on the luminescence properties of Nd3+ ion in a gadolinium scandium gallium garnet crystal,” Opt. Express20(9), 10393–10398 (2012). [CrossRef] [PubMed]
  45. E. J. McLaurin, L. R. Bradshaw, and D. R. Gamelin, “Dual-Emitting Nanoscale Temperature Sensors,” Chem. Mater.25(8), 1283–1292 (2013). [CrossRef]
  46. W. Xu, X. Gao, L. Zheng, Z. Zhang, and W. Cao, “Short-wavelength upconversion emissions in Ho3+/Yb3+ codoped glass ceramic and the optical thermometry behavior,” Opt. Express20(16), 18127–18137 (2012). [CrossRef] [PubMed]
  47. M. G. Nikolić, V. Lojpur, Ž. Antić, and M. D. Dramićanin, “Thermographic properties of a Eu3+ -doped (Y0.75Gd0.25)2O3 nanophosphor under UV and x-ray excitation,” Phys. Scr.87(5), 055703 (2013). [CrossRef]
  48. C. D. S. Brites, P. P. Lima, N. J. O. Silva, A. Millán, V. S. Amaral, F. Palacio, and L. D. Carlos, “Thermometry at the nanoscale,” Nanoscale4(16), 4799–4829 (2012). [CrossRef] [PubMed]
  49. S. A. Wade, S. F. Collins, and G. W. Baxter, “Fluorescence intensity ratio technique for optical fiber point temperature sensing,” J. Appl. Phys.94(8), 4743–4756 (2003). [CrossRef]
  50. C. Eckert, C. Pflitsch, and B. Atakan, “Sol–gel deposition of multiply doped thermographic phosphor coatings Al2O3:(Cr3+, M3+) (M = Dy, Tm) for wide range surface temperature measurement application,” Prog. Org. Coat.67(2), 116–119 (2010). [CrossRef]
  51. Z. Boruc, M. Kaczkan, B. Fetlinski, S. Turczynski, and M. Malinowski, “Blue emissions in Dy3+ doped Y4Al2O9 crystals for temperature sensing,” Opt. Lett.37(24), 5214–5216 (2012). [CrossRef] [PubMed]
  52. P. Haro-González, I. R. Martín, L. L. Martín, S. F. León-Luis, C. Pérez-Rodríguez, and V. Lavín, “Characterization of Er3+ and Nd3+ doped Strontium Barium Niobate glass ceramic as temperature sensors,” Opt. Mater.33(5), 742–745 (2011). [CrossRef]
  53. D. Jaque and F. Vetrone, “Luminescence nanothermometry,” Nanoscale4(15), 4301–4326 (2012). [CrossRef] [PubMed]

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