Polaronic Variable Range Hopping Mediated Electrical Transport Mechanisms in Ferromagnetic Pr2FeMnO6

Abstract

The electrical transport properties of oxide materials are largely dictated by electron-phonon interactions, which often lead to the formation of polarons, significantly influencing the conduction mechanism. In the case of the ferromagnetic orthorhombic perovskite oxide Pr₂FeMnO₆, the material exhibits insulating behaviour at room temperature, with a resistivity of approximately 4.1 × 10³ Ω·m. As the temperature decreases, the resistivity increases markedly, reaching 73.47 × 10³ Ω·m at 122 K, with a pronounced rise occurring below 160 K. To elucidate the conduction mechanism, the Variable Range Hopping (VRH) model is applied. This model describes electron hopping between non-nearest neighbour sites, which becomes favourable when the thermal energy is insufficient for nearest-neighbour hopping. Instead, electrons preferentially hop to sites with lower potential differences. The temperature dependence of resistivity is well-described by the VRH model, confirming its applicability in this system. In addition to electrical transport, the structural and magnetic properties of Pr₂FeMnO₆ have also been investigated. Notably, the material exhibits a magnetization reversal at low temperatures, further enriching its magnetic behaviour and potential applications.