Influence of Annealing Temperature on Structural, Optical, and Magnetic Properties of Pr2FeCrO6

The annealing effect is a complex phenomenon that may have structural and chemical impacts on the physical properties of materials. The variation in the annealing temperature provides an opportunity to tune the physical properties of materials. Structural, optical, and magnetic responses of the Pr₂FeCrO₆ (PFCO) sample are evaluated with rising annealing temperature. A single-phase PFCO compound was synthesized via a coprecipitation method and subsequently annealed at various temperatures ranging from 650 °C to 1200 °C to yield particle sizes of 70, 140, 280, and 465 nm, respectively. Structural studies based on the analysis of X-ray diffraction (XRD) patterns indicate the enhancement in crystallinity with the increment of annealing temperature. Unit cell parameters turned out to be greatly affected by annealing temperature. Unit cell distortion is considerably reduced and the lattice strain decreases with increasing annealing temperature. The variation of annealing temperature played a crucial role to modify the local structural environment of PFCO. The changes in the local structural environment with annealing are confirmed by electron density mapping of PFCO. The average particle size grows from 70 to 465 nm with the elevation of annealing temperature and is affirmed by a transmission electron microscope (TEM). The estimated energy band gap (E_g) is found to be decreased from 2.11 to 2.01 eV with an increasing particle size. M–H curves (at 10 K) for all the annealed samples indicate weak ferromagnetic behavior. Coercivity (H_c) is decreased, whereas saturation magnetization (M_s) is found to be increased with enlarging particle size. Temperature-dependent magnetization shows that the ferrimagnetic transition (T_c = 240 K) clearly appears and shifts toward lower temperature with escalating annealing temperature. These results indicate the pathways to optimize the properties of PFCO for magnetic storage and spintronics applications.