Effects of additives and annealing atmospheres on the microstructure of MnZn ferrite thin films

Manganese zinc ferrite thin films were prepared on quartz substrates buffered by a (00l) oriented ZnO underlayer by conventional rf magnetron sputtering method Mn-Zn-Fe oxide layers deposited on the ZoO underlayers were annealed in various atmospheres at 800°C for 5 hours. When the films were annealed either at reduced pressure in air or in N2 gas flow, single phase spinel-type ferrite was formed. Manganese zinc ferrite films annealed in N2 gas flow had excellent soft magnetic characteristics compared with the films annealed at reduced pressure in air because of their remarkable grain growth. Furthermore, Bi2O3 and V2O5 were added for the purpose of inducing crystal grain growth. Manganese zinc ferrite films with Bi2O3 were improved in their saturation magnetization because of their grain growth and good crystallinity. On the other hand, manganese zinc ferrite films with V2O5 showed excellent soft magnetic characteristics, when vanadium of 0.51 at.% was added.