NONSTOICHIOMETRY AND ITS EFFECT ON THE MAGNETIC-PROPERTIES OF A MANGANESE-ZINC FERRITE

The effect of oxygen nonstoichometry on physical and magnetic properties of a Mn-Zn ferrite has been studied by using annealed samples under various oxygen pressures and temperatures. The dependence of oxygen nonstoichiometry on disaccommodation and Fe2+ content changed at the stoichiometric composition, and the lattice parameter became maximum at the stoichiometric composition. These results suggest that Mn-Zn ferrites have two different defect structures: cation vacancies in cation-deficient regions and oxygen vacancies in anion-deficient regions. Initial permeability was maximum and power loss was minimum at the stoichiometric composition, suggesting the importance of the number of point defects for the magnetic properties.