Dielectric relaxation in glassy Se₉₀Ge_xIn_10-x

Abstract

Frequency and temperature dependence of dielectric constant (<b style=""><img src='/image/spc_char/italics_e.gif' border=0>'</b>) and dielectric loss (<b style=""><img src='/image/spc_char/italics_e.gif' border=0>''</b>) are studied in glassy Se₉₀Ge_xIn_10-x, where x = 0, 2, 4, 6, 8 and 10, in the frequency range 1-10 kHz and in the temperature range 293-400 K. The experimental results indicate that no dielectric dispersion exist in glassy Se₉₀Ge₁₀ alloy (x = 10). However, when In concentration increases (x = 8, 6, 4, 2 and 0), dielectric dispersion starts in the above frequency and temperature range. The values of <b style=""><img src='/image/spc_char/italics_e.gif' border=0>' </b>and <img src='/image/spc_char/italics_e.gif' border=0>'' at a particular temperature and frequency increase with the increase in In concentration. An analysis of the observed dielectric loss shows that the Guintini's theory of dielectric dispersion based on two electron hopping over a potential barrier is applicable in the present case.