Hasan M. Khan
The effect of TbNi substitution on the structural and magnetic properties of Sr0.5Ba0.5-xTbxNiyFe12-yO19, (x = 0.00–0.10; y = 0.00–1.00) hexaferrites that are synthesized by sol–gel auto combustion method is investigated. After synthesis of the samples by sol-gel method they were characterized by (FTIR) Fourier transform infrared spectroscopy, (XRD) X-ray diffraction, (SEM) scanning electron microscopy, (TEM) transmission electron microscopy and (VSM) Vibrating Sample magnetometery. Single phase of M-type hexa-ferrite structure has been confirmed by X-ray diffraction analysis. The lattice parameters were found to increase by increasing TbNi contents, and is thought of due to ionic sizes of the cations implicated. The TbNi has been completely soluble in the lattice. The scanning electron microscopy and transmission electron microscopy results clearly indicates that the grain size decreases with increase of TbNi substitution. The coercivity values (1640–2170 Oe) of all samples exhibits in the M-type hexaferrites range and shows increased anisotropy by the substitution of TbNi, while the size of nanoparticles was drastically reduced between 20 and 30 nm. The fine nanoparticles with increased anisotropy are very attractive in lot of applications, such as perpendicular recording media, high frequency applications and for improving signal to noise ratio.