Synthesis and Characterization of Nano-Hexagonal Calcium Ferrites

Abstract

The comparative study of substituted calcium hexaferrites samples with chemical composition CaCrxFe12-xO19 where, x= 0,2,4,6 have been chosen for their studies on structural and magnetic properties. Structural and morphological properties are studied by X-ray diffraction technique and scanning electron microscopy (SEM). The XRD pattern confirmed that the formation of single phase hexagonal ferrites with space group P63/mmc 167:R-3c. The SEM results confirms that the sample exhibit relatively well defined hexagonal like grains with average particle size found in between 24 to 40 nm. Magnetic characterization of the samples is carried out using vibrating sample magnetometer (VSM). The saturation magnetization (Ms), remanence (Mr) and coercivity (Hc) are found to decrease with increase in the value of substitution which is attributed to the occupation of sub lattice spin-up and spin-down sites by diamagnetic ions and anisotropy. The samples have a better signal-to-noise ratio, as the particle size was less than 50 nm, when calculated by Debye-Scherer formula and may be suitable for recording media.