Electrical conduction and dielectric relaxation in semiconductor SeSm0.005

The dc and ac conductivity of polycrystalline SeSM0.005 bulk samples have been measured under vacuum in the temperature range 363-93 K. The samples displayed dielectric dispersion in the frequency range 50 Hz-80 kHz. The calculated values of the exponent s of the function sigma = Aw(s) showed that correlated barrier hopping is the suitable model to describe the ac conduction mechanism. Calculation of the real dielectric constant (epsilon'), loss factor (epsilon) and loss tangent (tan delta) are given in the studied frequency and temperature ranges. The loss factor displayed a loss peak that gives direct evidence of the existence of a Debye relaxation type. Also, the arc shape of Cole-Cole diagrams has been used to determine and discuss the optical (epsilon(infinity)) and static (epsilon(s)) dielectric constants besides the macroscopic relaxation (tau(0)) and molecular relaxation (tau) times.