HIGH DIELECTRIC-CONSTANT AND VARIABLE-RANGE-HOPPING IN BI2SR2YCU2OY

The sample Bi2Sr2YCu2Oy prepared by solid state reaction method showed a single phase Bi-2212. DC resistivity measured in the temperature ra nge 77.5-300 K showed M-I like transition. AC conductivity measurement s were performed in the temperature range 80-473 K at different freque ncies. The conduction is by Mott's Variable Range Hopping. Various par ameters pertaining to the conduction process are evaluated. The value of dielectric constant epsilon increases with temperature and shows a very high value. For a given temperature the value is found to decreas e with increase in frequency.