Debye-type dielectric behavior of Bi-Sr-Ca-Cu-O-based transition-metal oxide glasses: Precursors for oxide superconductors

Detailed measurements of the frequency- (50 Hz to 10 kHz) and temperature (80 loss (ε’ ’) have been performed for the ${\mathrm{Bi}}_4$ ${\mathrm{Sr}}_3$ ${\mathrm{Ca}}_3$ ${\mathrm{Cu}}_{\mathit{y}}$ ${\mathrm{O}}_{\mathit{x}}$ (y=0 to 5) glasses. Some of these glasses become high-temperature superconducting oxides in their respective glass-ceramic phases. The dielectric properties of these glasses are found to follow a Debye-type relaxation behavior with relaxation frequency ${\mathit{f}}_{\mathit{c}}$ [=${\nu }_{\mathit{c}}$ exp(-${\mathit{W}}_{\mathit{c}}$/${\mathit{k}}_{\mathit{B}}$T)]. The relaxation behavior is thermally activated in nature similar to the dc electrical-conduction process of these glasses observed in our earlier investigation.