The optical constants (<i>n</i>, <i>k</i>) of single crystalline InBi have been determined using a two-angle method applying Fresnel’s equations. The complex dielectric constant was then calculated using the relation ε* = ε<sub>1</sub> − iε<sub>2</sub>, where ε<sub>1</sub> = <i>n</i><sup>2</sup> − <i>k</i><sup>2</sup> and ε<sub>2</sub> = 2<i>nk</i>. Assuming a free-electron model, the volume plasma resonance energy was found from the crossover position of the <i>n</i> and <i>k</i> curves to be 10.3 eV. The energy loss functions − Im[1/ε] and − Im[l/(ε + 1)], which have been interpreted as having maxima at the volume and surface plasma frequencies, respectively, when interband transitions are not significant, were plotted using the <i>n</i> and <i>k</i> data. These values were in general agreement with those obtained from the crossover point on the <i>n</i> and <i>k</i> curves and from the Ritchie relation <i>E</i><sub>s</sub> = <b><i>E</i></b><sub><i>v</i></sub>/√2.
© 1976 Optical Society of America 999
Roger L. Kroes, Roger C. Linton, and Frank E. Martin, "Vacuum-ultraviolet optical properties of single-crystal InBi," J. Opt. Soc. Am. 66, 999-1003 (1976)