Effect of La on Magnetic Properties of BaFe12O19

Abstract

Among the M-type hexaferrites, barium ferrites (BaFe12O19) have greatest technology interest due to its low cost and moderate magnetic properties. Magnetic properties can be tailored by changing processing condition and by suitable cationic substitution at Ba or Fe site. Lanthanum substituted (Ba1–xLaxFe12O19) and extra addition of lanthanum (BaFe12O19(Lax)) in barium hexaferrite are successfully prepared by solid state synthesis method. The structural, magnetic and microstructural characterizations are studied by X-ray diffractometer (XRD), mössbauer spectroscopy, vibrating sample magnetometer and scanning electron microscope (SEM), respectively. XRD patterns show single phase BaFe12O19 for La-substituted samples, whereas a secondary phase of barium mono-ferrite (BaFe2O4) is also detected for La-extra addition samples. Crystallite size is found to increase with La substitution. SEM shows the surface morphology of La-substitution and La-extra addition BaFe12O19. The magnetic properties show the variation in coercivity (Hc) and saturation magnetization (Ms) with La substitution and extra addition. Coercivity is found to decrease abruptly in La-extra addition samples, however, no such variation is observed for La-substituted samples. Ms is found to decrease for La-substituted barium hexaferrite, whereas Ms for La-extra addition samples first decreases and then increases to maximum value. © 2017 Indian Ceramic Society.