Parametrization of the Vibronic Contributions to the b40\text{}\text{}_{4}^{0} Spin-Hamiltonian Parameters for 8\text{}^{8}S7/2\text{}_{7}\text{}_{/}\text{}_{2} Ground State Ions in Fluoroperovskites

Parametrization of phonon induced contributions to the experimentally determined temperature dependence of the b$\text{}_{0}^{4}$ spin-Hamiltonian parameter for Gd$\text{}_{3+}$ doped RbCaF$\text{}_{3}$, CsCaF$\text{}_{3}$, RbCdF$\text{}_{3}$ and TlCdF$\text{}_{3}$ single crystals is discussed. Three physically different parametrization schemes are considered, i.e. that of Einstein, Debye and Huang. It is found that the model of Huang, which predicts that the phonon induced contributions should be proportional to the Debye-Waller factor, describes best the experimental data. The method allowing determination of the Debye temperature from EPR data is also suggested

Properties of amorphous silica generated by the fluoride method

A study of amorphous silica generated from mineral materials by the fluoride method and by different procedures of analysis., i.e., x-ray diffractio, x-ray fluorescence, IR spectroscopy, and nuclear magnetic resonance, is reported..