Structural and magnetic properties of La3+ substituted strontium hexaferrite nanoparticles prepared by citrate precursor method

Lanthanum (La3+) doped strontium ferrite is a promising material for high density perpendicular recording media due to high magnetocrystalline anisotropy and coercivity. The effects of La3+ on magnetic properties have been analyzed using vibrating sample magnetometer and discussed. The results show that the coercivity has been improved by substitution of La3+ on iron sites; coercivity value found to be increased with increase in La3+ content and is maximum for x=0.63 in SrLaxFe12-xO19, indicating the high magnetocrystalline anisotropy. La3+ doped strontium ferrite, prepared by citrate precursor technique, have been analyzed by means of X-ray diffraction (XRD), field emission scanning electron microscopy, fourier transform infrared spectroscopy and inductance capacitance resistance meter bridge. The XRD analysis shows that crystalline ferrite phase with hexagonal structure (P6(3)/mmc) have been formed when the precursor calcined at 900 degrees C for 5 h. The crystallite size is found in the range of 31-38 nm and the elemental composition has been examined by energy dispersive X-ray. The dc electrical resistivity has been found to be increased with increasing La3+ content. (C) 2012 Elsevier B.V. All rights reserved.