Electrical and Dielectric Spectroscopic Characterization of Polycrystalline Dy2Si2O7

The compound Dy2Si2O7 exists in two polymorphs, the low temperature triclinic phase (type B) and a high temperature orthorhombic phase (type E). The dc and ac electrical conductivities of E-Dy2Si2O7 are measured in the temperature range 290-510 K and frequency range 1 kHz to 1 MHz. The dc electrical transport data are analyzed according to Mott's variable-range hopping model. The disorder parameter (T-o) and density of states at fermi level are obtained. The ac conductivity sigma(ac) (omega) is obtained through the dielectric parameters. The ac conductivity can be expressed as sigma(ac) (omega) =B omega(s), where s is slope and it decreases with increase in temperature. The conduction mechanism in the compound is discussed in low and high temperature regions in the light of theoretical models.