Detailed analysis of lanthanum impact on structural, morphological and magnetic properties of manganese spinel ferrites (MnLaxFe2-xO4 x = (0.0, 0.1, 0.2) synthesized through hydrothermal technique

Abstract

Hydrothermal method was used for the preparation of lanthanum (La) substituted manganese (Mn) ferrites (MnLaxFe2-xO4, x = 0.0, 0.1, 0.2) to study the effects of La substitution on structural, morphological, and magnetic characteristics. Experimental characterizations such as X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive spectrum (EDX), Fourier transform infrared spectroscopy (FTIR), Vibrating sample magnetometer (VSM) and Two Probe technique were employed on the prepared samples. A single-phase spinel structure was confirmed by XRD results and lattice parameter increased from 8.40 Å to 8.51 Å with increasing La3+ contents. SEM micrographs showed nanoparticles are agglomerated and non-uniform in size. EDX analysis confirmed that substitution has been successfully achieved. The Raman spectra confirmed that the Raman mode is around 142 cm−1 for pure manganese ferrite and this Raman mode shifted towards lower frequency with increasing the La3+ content. The FTIR spectrum revealed the absorption band of octahedral site is around 650 cm−1 for pure Mn ferrite and this band shifted towards lower frequency with increasing the La3+ content because substitution of La increases the bond length. The M−H loops justified that substitution of nonmagnetic La3+ causes to decrease the saturation magnetization (Ms) as well as coercivity (Hc). The substitution of La3+ increases the resistivity of the Mn ferrite which will make these materials favorable for such applications where low eddy current losses is a primary requirement.