Determination of density of defect states in glassy Se98M2 (M = Ag, Cd and Sn) alloys using a.c. conductivity measurements

•The metal-induced effect on the defect states is studied.•Thermally activated a.c. conduction is studied in the present samples.•Correlated barrier hopping is also verified in the present study.

In the present work, we have used a.c. conductivity measurements as a powerful tool to estimate density of defect states in some glassy alloys. For this, we have studied the temperature and frequency dependence of a.c. conductivity of binary glasses of Se98M2 (M = Ag, Cd and Sn) system. The a.c. conductivity, σac (T, ω) is found to obey the universal law σac (T, ω) ∝ ωs. The agreement between experimental and theoretical results of a.c. conductivity suggests that the thermally activated a.c. conduction in binary glassy Se98M2 (Ag, Cd and Sn) system can be successfully explained using correlated barrier hopping (CBH) model. The optimum values of different electrical parameters are obtained in case of glassy Se98Sn2 alloy. The results confirm the dominance of bi-polaron hopping over single-polaron hopping in present glassy alloys.

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