Dielectric Dispersion in Yttrium and Erbium Formate Dihydrate Crystals

摘要

The dielectric properties of Y(HCOO)_3·2H_2O and Er(HCOO)_3· 2H-2O are studied. The frequency dependences (0.01 Hz to 20 kHz) of the real (ε′) and imaginary (ε″) parts of dielectric permittivity (ε = ε′ - iε″) are shown to follow a fractal scaling law for the dielectric response of solids. In the tan δ versus temperature curves, a number of maxima are revealed in a narrow temperature range. The experimental data are used to evaluate the activation energies of relaxation processes. The observed anomalies are assumed to be associated with changes in the dynamics of protons in hydrogen bonds.