High Dielectric Constant and Variable Range Hopping in Bi₂Sr₂YCu₂O_y

The sample Bi₂Sr₂YCu₂O_y prepared by solid state reaction method showed a single phase Bi-2212. DC resistivity measured in the temperature range 77.5–300 K showed M–I like transition. AC conductivity measurements were performed in the temperature range 80–473 K at different frequencies. The conduction is by Mott's Variable Range Hopping. Various parameters pertaining to the conduction process are evaluated. The value of dielectric constant ε increases with temperature and shows a very high value. For a given temperature the value is found to decrease with increase in frequency.