Novel perovskite–spinel composite approach to enhance the magnetization of LaFeO3

Abstract

In the present work, the perovkite–spinel interface effect on the bulk magnetic behavior of lanthanum ferrite (LaFeO₃) based composite systems is under investigation in view of the enhancement of the magnetization of LaFeO₃. By using LaFeO₃ as the perovskite phase and NiFe₂O₄ as the spinel phase with the compositions x = 0, 20, 30, 40 and 100 wt%, a composite system is developed by mechanical mixing. The structures are confirmed using X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). Physical interaction at the interface of the LaFeO₃ and NiFe₂O₄ phases is realized by XRD peak broadening and shifting. The M–T and M–H curves are closely monitored to investigate the perovskite–spinel interface effect on the bulk magnetic behavior of the composites. Significant enhancement in the magnetization of the perovskite–spinel composite phase with a 60% LaFeO₃–40% NiFe₂O₄ composition over individual phases is detected. The composition effect up to 60 : 40 of LaFeO₃–NiFe₂O₄ is considered to preserve the dominance of the LaFeO₃ phase. The spin coupling mechanism across the interface is speculated for the enhancement of the magnetization in the composite. Mössbauer spectroscopic investigation confirms the co-existence of magnetization in the composites.