The composition, transparency, refractive index, and infrared reflectance of yttria-stabilized cubic hafnia (c-HfO2) single crystals were measured. The material is transparent from the ultraviolet to the mid-infrared and for 9.6-mol % Y2O3, the index is slightly smaller than for comparable cubic zirconia c-ZrO2 or for diamond, but the dispersion (nF - nc = 0.02811) is larger than that of diamond. The index vs wavelength from 0.36 µm in the ultraviolet to 5.0 µm in the infrared is represented by a three-term Sellmeier formula to 1 × 10-4. The temperature dependence of refractive index is similar to that of c-ZrO2. The infrared reflectance spectrum is fitted in a classical dispersion analysis with seven oscillators derived from the transverse optical phonon as well as acoustic frequencies with splittings due to lowered symmetry derived from the randomly distributed stabilizer ions.
© 1990 Optical Society of America
D. L. Wood, Kurt Nassau, T. Y. Kometani, and D. L. Nash, "Optical properties of cubic hafnia stabilized with yttria," Appl. Opt. 29, 604-607 (1990)