Variable-range-hopping conduction and dielectric relaxation in Pr0.6Sr0.4Mn0.6Ti0.4O3±δ perovskite

• Conductivity and dielectric properties of Pr0.6Sr0.4Mn0.6Ti0.4O3±δ were analyzed.
• DC conductivity exhibited a VRH model.
• Dielectric relaxation is due to the trap-controlled AC conduction.
• Conduction mechanism at low temperatures is governed by the grain boundaries effect.

Pr0.6Sr0.4Mn0.6Ti0.4O3±δ perovskite was prepared by the solid-state reaction technique. Preliminary room-temperature structural studies confirm the formation of the sample in the orthorhombic structure. The dielectric properties of the studied sample have been investigated in 10−1–106 Hz and 113–303 K, frequency and temperature ranges respectively. The alternative current (AC) conductivity shows a power law σ1∝ωn behavior and with a decrease of frequency exponent n as temperature decreases. The temperature dependence of the direct current (DC) conductivity, σ∝σ0 exp(−B/T1/4), exhibits a variable-range hopping model. The activation energy for the variable-range hopping conduction is comparable to that for the dielectric relaxation at lower temperatures but slightly higher at higher temperatures suggesting that the dielectric relaxation is due to the trap-controlled AC conduction. Detailed studies of electrical properties of the material using complex impedance spectroscopy technique exhibit that the impedance and related parameters are strongly dependent upon temperature and microstructure (bulk, grain boundary, etc...).