基片对交替溅射制备的MnZn铁氧体薄膜结构和磁性的影响

使用成分分别为MnFe₂O₄和ZnFe₂O₄的靶，使用射频溅射交替沉积制备了成分不同的Mn_1-xZn_xFe₂O₄薄膜，沉积薄膜所用基片分别为单晶硅Si（100），氧化的单晶硅SiO₂/Si（100）, ZnFe₂O₄为衬底的单晶硅ZnFe< 关键词： MnZn铁氧体 纳米晶 软磁性 磁性薄膜

The effect of substrates on magnetic properties and structure of MnZn ferrite films by alternate deposition

Mn_1-xZn_xFe₂O₄ films were prepared by alternative rf-sputtering from targets of MnFe₂O₄ and ZnFe₂O₄. The films were deposited on substrates such as single-crystal Si（100）, oxidized single-crystal Si（100）, single-crystal Si（100） with ZnFe₂O₄ underlayer and single-crystal MgO（100）. The deposited films are amorphous. After annealing in vacuum furnace at 550℃, the polycrystalline Mn-Zn ferrite crystallizes. The film with composition of Mn_0.5 Zn_0.5 FeO₄ shows better magnetic properties: high magnetization M_s and lower coercivity H_c. The coercivity of the film deposited on MgO（100） substrate is the lowest. In this paper, the influences of substrate on film structure and the magnetic properties are investigated. It is believed that the magneto-elastic anisotropy resulting from stress in films dominates the coercivity of Mn-Zn ferrite films. The grain size may be refined to nanometer scale instrumentally by using suitable substrate; the stronger exchange coupling between grains would lead to a lower magneto-elastic anisotropy by averaging to the grains. Therefore, the soft magnetic properties of Mn-Zn ferrite films are improved.