Structural, micro-structural/morphological and magnetic properties of RECrO3 (RE = La, Nd, Sm, Eu and Gd) Orthocromites

TL;DR

This study investigates the structural, morphological, and magnetic properties of RECrO3 orthorhombic compounds with various rare earth elements, revealing phase structures, grain growth behavior, and magnetic transitions, including antiferromagnetic and spin-reorientation phenomena.

Contribution

It provides detailed synthesis, structural characterization, and magnetic analysis of RECrO3 compounds with different rare earths, highlighting how rare earth variation influences properties.

Findings

All samples crystallize in orthorhombic structures with specific space groups.

Grain sizes vary from 1.0 to 3.0 micrometers depending on the rare earth element.

Antiferromagnetic transition observed in all samples at different temperatures.

Abstract

We report here the structural, micro-structural/morphological and detailed magnetic properties of RECrO3 (RE = La, Nd, Sm, Eu and Gd) Orthocromites. A series of RECrO3 (RE = La, Nd, Sm, Eu and Gd) Orthocromites polycrystalline samples with uniform particle size were synthesized via standard solid-state reaction method. LaCrO3 (LCO), NdCrO3 (NCO), SmCrO3(SCO), and EuCrO3 (ECO) crystallizes in single phase of orthorhombic structure with Pnma (No.62) space group while GdCrO3 (GCO) found to crystallize in orthorhombic phase with Pbnm space group. SEM images confirms the systematic growth of all studied samples grain growth takes place during the sintering process and images shows the polyhedral shape with varying average grain size ranging from approximately 1.0{\mu}m to 3{\mu}m confirm the bulk synthesis of studied RECrO3. Lowest average grain size (~ 1.1{\mu}m) was observed for LaCrO3 and maximum (~ 2.8{\mu}m) for EuCrO3. The shapes of the grain size changes because of crystal lattice distortion induced by various rare earths (La, Nd, Sm, Eu and Gd) at A site. Energy dispersive X-ray Analysis (EDAX) reveals the elements confirmation in different studied RECrO3 samples. Within the detection limit of EDAX no impurity elements were observed in different as synthesized RECrO3 samples. Temperature dependent DC magnetization (M-T) studies showed an antiferromagnetic transition (TN) attributed to Cr3+ spins in all samples at different temperature. At low temperature spin-reorientation (TSR) of rare earth ion was also observed in NCO, SCO at around 50K and the same is observed at around 30K in ECO and the same was missing in GCO because of large moment of Gd3+ ions attributed by ground state spectroscopic term 8S7/2 by external applied magnetic field. The magnetization versus applied magnetic field (M-H) loops exhibited ferromagnetic like behavior at 10K and 100K and paramagnetic at 300K for GCO.