Study of some structural and magnetic properties of Mn-substituted SrCu hexagonal ferrites

Y-type hexagonal ferrite samples with the composition Sr 2 Cu 2 - x Mn x Fe 12 O 22 ( x = 0.0 , 0.4, 0.8, 1.2, 1.6 and 2.0), have been prepared by the ceramic method. The X-ray diffraction patterns at room temperature show that the prepared samples have a single phase and the effect of composition on the unit cell parameters, density and porosity has been studied. The variation of the initial magnetic permeability ( μ i ) with temperature for all the investigated samples in the temperature range (300–780 K) has shown three regions of behaviour which has been explained on the basis of the proportionality μ i ∝ M s 2 / K eff —where M s is the saturation magnetization and K eff is the effective magnetocrystalline anisotropy constant—along with the expected distribution of both Mn and Cu ions in the lattice. The temperature dependence of selectivity for a chosen frequency ( f = 1.6 MHz ) for the six investigated samples has also been studied.