Bulk magnetic properties of tetravalent ion substituted Cu-ferrite

Abstract

The lattice parameter,a, increases with the increase of Ti⁴⁺ substitution while it decreases with the increase of Ge⁴⁺ substitution in Cu_1+x A _x Fe_2−2x O₄ compounds [A=Ti⁴⁺, Ge⁴⁺Sn⁴⁺]. On substitution of Sn⁴⁺,a does not vary. CuFe₂O₄ exhibits single domain (SD) behaviour that changes to multi domain (MD) type on Ti⁴⁺ substitution. On Ge⁴⁺ substitution initially all the compositions exhibit SD behaviour while forx>0.2 they show MD behaviour. All Sn⁴⁺ substituted compositions exhibit SD behaviour. The Curie temperature decreases on addition of Ti⁴⁺, Sn⁴⁺ and Ge⁴⁺. The magnetic momentn _B (77 K) initially increases and then decreases with the substitution of Ti⁴⁺, Ge⁴⁺, and Sn⁴⁺. This is explained by cation distribution and reduction of Fe³⁺ ions.