Structural and magnetic studies of Co-Ti-substituted magnetoplumbite-type (M-type) strontium ferrites by sol-gel method

Magnetoplumbite-type (M-type) strontium ferrites doped with varying molar ratio of cobalt and titanium (SrFe12-2x Co (x) Ti (x) O-19; x = 0.2, 0.4, 0.6, 0.8 and 1.0) were prepared via sol-gel technique employing ethylene glycol as a gel precursor. The prepared samples were characterized using X-ray diffractometry (XRD), field emission scanning electron microscopy, superconducting quantum interference devices and high-resolution transmission electron microscopy (HRTEM). The XRD patterns confirmed the formation of a highly homogeneous M-type strontium ferrite at molar substitution of 0.2 in the SrFe12-2x Co (x) Ti (x) O-19 system (SF02) with calculated crystallite size of 48.5 nm. Sample SF02 showed the desired magnetic properties of a reduced coercivity at 4946 (192) Oe while having enhanced remnant and saturation magnetizations of 30.33 (0.81) and 61.45 (2.14) emu/g, respectively. HRTEM imaging of SF02 showed high regularity in the stacking sequence with corresponding lattice spacings matching that commonly found in the M-type ferrite structure.