To Synthesize and Study Electrical Properties of Strontium Hexaferrites Doped with Magnesium, Cobalt and Lithium

Abstract

There has been a tremendous interest in hexagonal ferrites during the last ten years for a number of marvelous applications. “Due to their expended use”, hexaferrites has become very important magnetic material being commercially produced. Strontium based M type hexaferrites, SrFe12O19 is one of such material that is currently used in these applications. In the current work cobalt, magnesium and lithium dopant substitution is performed in series of SrFe(12-3x)(Co,Mg,Li)xO19 (x=0.0,0.15,0.25,0.50) using sol gel method. The aqueous solution, containing metal nitrates were brought in use to prepare strontium hexaferrites nanoparticles. The prepared samples were then calcined at 950 ⁰C for 4 hours. The synthesized samples were then characterized using X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and Fourier Transform Infra-Red Spectroscopy (FTIR). Impedance analyzer and LCR meter was used for performing dielectric measurements. The formation of hexagonal SrFe(12- 3x)(Co,Mg,Li)xO19 was confirmed using XRD. Debye Scherer equation was used to find out the crystallite size that was in range of 37 nm-57 nm. The band positions were studied using FTIR. The study of dielectric properties with change in frequency was done at room temperature. For the cobalt, magnesium and lithium doped strontium hexaferrite nanoparticles the real part of dielectric constant enhanced to 77.8 at 250 Hz for x=0.5. the value of dielectric loss for cobalt, magnesium and lithium doped strontium hexaferrite nanoparticles has increased from 2.21 to 54.0 at 250 Hz. Ac conductivity values also showed increase in cobalt, magnesium and lithium doped strontium hexaferrite. AC conductivity results explains that electron hopping governs the conduction process. The electrical properties and conductivity rises with increasing concentration of cobalt, magnesium and lithium. The enhanced dielectric properties and increase in conductivity of the prepared nanoparticles make it applicable in field of super capacitors and charge storage devices.