Role of Zr–Co substitution at iron site on structural, magnetic and electrical properties of Sr-hexaferrites nanomaterials synthesized by the sol–gel combustion method

Abstract

The sol–gel auto-combustion technique has been employed to synthesize the M-type Sr-hexaferrites nanomaterials substituted with binary mixture of zirconium and cobalt at the iron site. The phase purity of the samples is confirmed by X-ray diffraction analysis and the crystallite size is found in the range of 31–45nm. The scanning electron microscopic analysis also confirms that the particles are in nanosize (25–50nm). The magnetic parameters like saturation magnetization, remanence, squareness ratio and the coercivity are calculated from the hysteresis loops. The values of saturation magnetization and remanence increase with the increase in Zr–Co content up to x=0.4 while the coercivity decreases continuously with the substituents. The squareness ratio is above 0.5 which indicates that the samples are in single magnetic domain. The room temperature DC electrical resistivity is measured by the two point probe method and is found to increase with Zr–Co content up to the substitution level of x=0.6. These materials can be used in microwave devices as these devices require highly resistive materials with low eddy current losses.