The structural and magnetic properties, non-Debye relaxation and hopping mechanism in PbxNd1−xFeO3 (where x = 0.1, 0.2 and 0.3) solid solutions

Abstract

Nd1−xPbxFeO3 (x = 0.1–0.3) solid solutions were prepared by aliovalent substitution of Pb2+ at the Nd3+ site using the conventional solid-state reaction route. The structural, magnetic and dielectric properties and hopping mechanism of these solid solutions are reported. XRD data shows that all the samples possessed orthorhombic crystal structures. No impurity phase was found, indicating that Pb2+ was well within its solid solubility limit. All samples exhibited magnetic ordering with the Mr value decreasing from 2.42 emu/g for the x = 0.1 sample to 1.79 emu/g for the x = 0.3 sample. The coexistence of the multi-valance state of the Fe ion was explored using XPS analysis. The dielectric constant (ε׳) and dielectric loss (ε״) were found to decrease with increases in the frequency of the applied electric field and to show Cole–Cole relaxation behavior. The temperature-dependent variation of exponent “n” (obtained from the Jonscher’s power law fitting) explains the conduction model that the system follows exactly.

Keywords

• Orthoferrites
• dielectric properties
• magnetic properties
• Cole–Cole relaxation
• hopping mechanism