Structural, electrical, dielectric properties and complex impedance analysis of Pr0.6Sr0.4Mn1−xAxO3 perovskites (A = Cr and Ti)

In this setting, we prepared the Pr0.6Sr0.4Mn0.95A0.05O3 (A = Cr and Ti) compound by the solid-state reaction. The electrical, dielectric properties and complex impedance analysis were investigated by admittance spectroscopy over a wide range of temperatures and frequencies. The Pr0.6Sr0.4MnO3 sample doped by chromium presents a metal behavior at low temperature and a semiconductor one at high temperature. The semiconductor to metal transition is followed by a decrease of the conductivity below 100 K. A semiconductor behavior is noticed for the other composition doped by titanium. The activation energy decrease from 75.68 to 69.66 meV for A = Ti and A = Cr, respectively. The total conductance spectrum of Pr0.6Sr0.4Mn0.95Cr0.05O3 and Pr0.6Sr0.4Mn0.95Ti0.05O3 compound are well described by the Jonscher power law: $$G\left( \Omega \right)\; = \;G_{{{\text{dc}} }} \; + \;A\Omega^{m}$$ . The exponent ‘m’ changes with Ti and Cr doping element. The real part of the permittivity increases with increasing temperature and more stability with doping element Ti than Cr. Impedance study for the samples indicate the presence of metal–semiconductor transition only with chromium and a non-Debye relaxation phenomenon related to a grain and grain boundary medium can be modulated the material by an electrical equivalent circuit.