Far-infrared evidence for glass-like properties exhibited by crystals of CaF2 doped with YF3
Low temperature far-infrared transmission measurements between 3 cm-1 and 18 cm-1 have been performed on crystals of CaF2 doped with YF3 for molar concentrations ranging from 1% to 22%. These single crystal materials posses a broad distribution of two-level systems typical of amorphous materials. The distribution is similar in magnitude and frequency dependence to that of a standard soda-lime silica glass. In contrast to other fluorite mixed crystal systems the magnitude of the two-level system distribution for YF3 doped samples can be reversibly altered by high temperature cycling between 600 and 900 C.
Fitzgerald, S.A., J.A. Campbell, and A.J. Sievers. 1996. "Far-infrared evidence for glass-like properties exhibited by crystals of CaF2 doped with YF3." Journal of Non-Crystalline Solids 203: 165-171.
Journal of Non-Crystalline Solids
Physics and Astronomy