Influence of Calcination Temperature on Structural, Morphological and Magnetic Properties of M-Type Strontium Hexaferrite Powder Prepared by Sol-gel Auto Combustion Route

Strontium hexaferrite (SrFe12O19) nanopowders have been synthesized using sol-gel auto combustion route. Ferrite precursors were obtained from aqueous mixtures of strontium nitrate and ferric nitrate nonahydrate. Citric acid (C6H8O7), was added to the mixed solution as fuel. The effect of calcination temperature on the structural, morphological, magnetic properties and phase formation of synthesized SrFe12O19 nanopowder was investigated and discussed in details. The material properties were studied employing X-ray diffraction (XRD), Raman spectroscopy, SEM, and a vibrating-sample magnetometer (VSM). The calcined products and the formation of crystalline phase were analyzed via XRD technique which revealed the SrM single phase formation at calcined temperature 1100oC with a crystallite size of 76.107 nm. The Rietveld refinement technique as applied in the Fullprof program was utilized for determining the resulting crystalline phase's amounts, lattice parameters, Bragg R-factor and refined structure value χ2. Raman analysis verified the development of the whole crystallographic hexaferrite locations and the whole peaks in the sample related to Raman vibration modes as well as M-type structures. Additionally, the resulted outcomes verified that the prepared material was SrFe12O19 and its density (ρ_x) reduced as its calcination temperature increased up to 1100°C. The sample material's magnetic analysis at the room temperature elucidated a higher coercivity value of (4610 Oe), a saturation magnetization of (66.285 emu/g), and a remnant of 38.90 emu/g.