TRANSPORT AND MAGNETIC PROPERTIES OF SrTi₂Zn₂Fe₁₀O₂₂ HEXAFERRITE

A new compound with a chemical formula SrTi₂Zn₂Fe₁₀O₂₂ has been synthesized using analar grade reactants by solid-state diffusion technique at 1173°K for 100 hour. The formation of the compound is checked by X-ray diffractometry with filtered Cu radiation. The structural result shows that the compound is in a single hexagonal phase without traces of unreacting phases of the reactants. The observed unit cell dimensions are a = 5.891 Å and c = 46.064 Å. The compound is studied magnetically by using Gouy’s balance and the result shows that it is ferrimagnetic at room temperature (Curie temperature T_C=334°K). From the paramagnetic behaviour of the compound above the critical temperature, Curie molar constant is worked out and is found to be 42.67, matching with the expected value for stable oxygen states of the cations in the molecule. Electrical conductivity measurement shows slight deviation from linearity near Curie temperature with activation energy 0.44 eV. In addition to these, the compound is analyzed by thermo-gravimetry, scanning electron microscopy and infrared absorption. The thermo-gravimetric analysis shows the compound is thermally stable upto 1273°K; the microstructural study (SEM) shows clearly hexagonal platelets with average particle size 2.263 μm where as the infrared absorption gives two absorption peaks as observed in spinel structures in the range 400 cm⁻¹ to 4600 cm⁻¹, which may be due to octahedral and tetrahedral complexes present in the compound.