Enhancement Of Magnetic Properties Of Calcium Hexaferrites With Aluminium Substitution

Abstract

Ferrites are large class of oxides with astonishing magnetic properties, which have been investigated and applied for the past 50 years. Their applications range from millimeter wave integrated circuitry to magnetic recording & microwave devices. These applications are based on very basic properties of ferrites; such as significant saturation magnetization, high electrical resistivity, low electrical losses, and good chemical stability. Ferrites can be obtained in different crystal systems by many methods, and the feasibility in preparation opens the means to tailor their properties for many applications. By reducing the scale to the Nanometric size, new and technologically interesting properties have been obtained. In the current study, Structural and Magnetic properties of Aluminium substituted calcium hexaferrites are reported. A series of Aluminium substituted Calcium hexaferrite samples, have been prepared by Solution combustion synthesis. XRD patterns confirmed the formation of Hexagonal phase with space group P63/mmc. Lattice parameter values decreased with Al3+ content. Magnetic properties such as saturation magnetization (Ms), remanence (Mr) and magneton number (nB) were found to decrease, while the coercivity (Hc) and reduced remanence (Mr/Ms) of the samples were found to increase with increasing Al3+ content. Results of VSM studies show the decrease in saturation magnetization with increase in Al concentration. However, the coercivity and Retentivity increased with Al concentration. The high values of retentivity and coercivity make these materials best for high-density recording media and permanent magnets. Our work suggests that, substitution can be used to alter magnetic property. This is the encroachment for selecting suitable materials for various technological applications.