Magnetic and microstructural properties of Sn/Nb substituted Mn-Zn ferrites

Saturation magnetisation, Curie temperature and initial permeability of Sn/ Nb substituted Mn-Zn ferrites have been studied at room temperature. The in fluence of high valency cations on the microstructure has been studied. Gra ins of monodomain form are obtained and the variation of initial permeabili ty with grain size is discussed in the light of recent studies on Mn-Zn fer rites, where initial permeability variation with grain size was explained o n the basis of the Pankert model. The variation of saturation magnetisation and Curie temperature with dopant cation concentration is explained. (C) 1 999 Elsevier Science S.A. All rights reserved.