Effects of Additives and Annealing Atmospheres on the Microstructure of MnZn Ferrite Thin Films

摘要

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 ZnO underlayers were annealed in various atmospheres at 800 deg C for 5 hours. When the films were annealed either at reduced pressure in air or in N_2 gas flow, single phase spinel-type ferrite was formed. Manganese zinc ferrite films annealed in N_2 gas flow had excellent soft magnetic characteristics compared with the films annealed at reduced pressure in air because of their remarkable grain growth. Furthermore, Bi_2O_3 and V_2O_5 were added for the purpose of inducing crystal grain growth. Manganese zinc ferrite films with Bi_2O_3 were improved in their saturation magnetization because of their grain growth and good crystallinity. On the other hand, manganese zinc ferrite films with V_2O_5 showed excellent soft magnetic characteristics, when vanadium of 0.51 at. percent was added.