Chapter IV molecular and ionic interactions in dielectrics chemical aspects

A considerable number of investigations of the optical constants of elements at optical and infrared frequencies were reported. The indices of refraction of liquid and solid argon were measured between 84 and 95°K and 84 and 74°K, respectively¹, The dielectric constant of liquid He³ under pressures from 0.2 to 29.5 atm, in the temperature range 0.14 to 1°K was determined². Measurements of the reflectivity of crystalline Ge in the 7.6 to 18.0 ev region were employed to calculate the index of refraction and the extinction coefficient in the range 0 to 18 ev³. In the infrared region, the optical constants⁴ and the temperature dependence of the index of refraction⁵ of Ge were characterized. Hodgson⁶ reported the optical constants of liquid Ge, Sn and Sb between 4000 and 27000 cm⁻¹, and the same properties were measured for Sb at longer wavelengths, up to 12 µ, at temperatures between 110 and 290°K⁷. In the frequency region of the intrinsic absorption edge in polarized light, a determination of the optical constants of single-crystal, hexagonal Se was reported⁸. The optical constants of colloidal Au were measured by Rőmer and v. Fragstein⁹, and Hodgson¹⁰ further reported these quantities for liquid Ag from 4000 to 17000 cm⁻¹. Hass and Waylonis¹¹ measured the reflectance and transmittance of Al films in the visible and ultraviolet spectrum. A numerical calculation of the optical constants of the noble metals of f.c.c. structure, on the basis of the band model, was given by Suffczynski and Michaelson¹².