Disorder Effects in La substituted ferrimagnetic Ca2FeMoO6 double perovskite

TL;DR

This study investigates how La substitution affects the structural, magnetic, and electrical properties of Ca2FeMoO6 double perovskite, revealing increased disorder, phase stabilization, and property modifications with La doping.

Contribution

It provides new insights into the disorder effects and property tuning in La-doped Ca2FeMoO6 double perovskites through comprehensive characterization.

Findings

Increased La doping stabilizes monoclinic phase and expands lattice.

La doping suppresses secondary phases and increases Mo incorporation.

Magnetic and electrical properties are significantly altered by disorder.

Abstract

Ca2-xLaxFeMoO6 double perovskite with La concentration x = 0 to 0.6 was synthesized using solid state sintering route. The standard techniques of XRD, SEM and EDX were applied to characterize the material. Crystal structure of the samples was stabilized in monoclinic phase with space group P2I/n and lattice expansion was indicated with the increase of x. The increase of La concentration gradually suppressed the coexisting minor secondary phase in the material and simultaneously, EDX results indicated the accommodation of more Mo atoms in the crystal structure. A significant modification in the surface morphology of the material was noted from adhesive type surface for x = 0 to brittle type surface with more grain boundary contributions for La doped samples. We understand a significant change in magnetic properties (appearance of cluster glass component, reduction of magnetic moment and indication of higher TC) and in electrical properties (reduction of metallic character) in terms of enhanced internal disorder in the material, introduced due to La doping in double perovskite structure.