Abstract:
Hydrothermal method was used for the preparation of lanthanum substituted
manganese ferrites (MnLaxFe2-xO4, x= 0.0, 0.1, 0.2) to study the effect of substitution
on structural, morphological and magnetic characteristics. Experimental
characterizations such as X-ray diffraction (XRD), Scanning Electron microscopy
(SEM), Energy Dispersive X-ray spectrum (EDX), Fourier transmission infrared
spectroscopy (FTIR), Vibrating sample magnetometer (VSM) and two probe technique
were used to characterize the samples. A single-phase spinal structure was confirmed
by XRD and lattice parameter was increased from 8.40 Å to 8.51 Å. SEM micrographs
showed nanoparticles are agglomerated and are non-uniform in size. EDX analysis
confirmed that substitution has been successfully achieved. The Raman spectra
confirmed that the Raman mode is around 142cm-1
for pure manganese ferrite and this
Raman mode shifted towards lower frequency with increasing the La content. The FTIR
spectrum revealed that the absorption band of octahedral site is around 650 cm-1
for
pure manganese ferrite and this band shifted towards lower frequency with increasing
the La content because substitution of La increases the bond length. The M-H loops
justified that substitution of nonmagnetic La+3 (0μB ) has decreased the saturation
magnetization (Ms) and decreased the coercivity (Hc). The substitution of La increased
the resistivity of the manganese ferrite which will make the material suitable for high
frequency applications where low eddy current losses are desirable.
