Optical and magnetic properties of La 1−x Ga x FeO 3 nanoparticles synthesized by polymerization complex method

Abstract La 1− x Ga x FeO 3 ( x = 0.0, 0.1, 0.2, 0.3 and 0.4) nanoparticles were synthesized by polymerization complex method. X-ray diffraction (XRD) results reveal a pure orthorhombic phase structure. Increasing of Ga content, resulting in the decrease of average crystallite sizes calculated by XRD from 58.4 ± 5.9 to 13.4 ± 4.3 nm and the average particle sizes estimated by transmission electron microscope (TEM) images from 70.2 ± 4.5 to 21.4 ± 8.5 nm. The optical band gaps determined by UV–vis spectra showed a redshift from 2.145 to 1.954 eV that originates from surface effect caused by Ga substitution. The magnetic properties were investigated using a vibrating sample magnetometer (VSM). The room temperature hysteresis loops of La 1– x Ga x FeO 3 nanopowders indicate the antiferromagnetic behavior of pure sample and all doped samples of ferromagnetic behavior with the enhancement of coercive field ( H c ), remanence ( M r ) and magnetization ( M ) due to the more disordering spins induced at the surface of particle. It is evident from field cool (FC) measurement of La 0.6 Ga 0.4 FeO 3 sample that the Curie temperature ( T c ) is above 350 K.