Fe_3O_4/MgO(100)薄膜的激光分子束外延与磁电学性能  

Magnetic and electrical properties of Fe_3O_4 thin films on MgO(100) substrates by laser molecular beam epitaxy

作　　者：曹林洪[1,2] 吴卫东[1] 唐永建[1] 葛芳芳[1] 白黎[1] 王学敏[1] 

机构地区：[1]中国工程物理研究院激光聚变研究中心,四川绵阳621900 [2]西南科技大学材料科学与工程学院,四川绵阳621010

出　　处：《强激光与粒子束》2009年第12期1819-1823,共5页High Power Laser and Particle Beams

基　　金：等离子体物理国家级重点实验室基金项目(9140C680240903)

摘　　要：采用激光分子束外延方法,以烧结-αFe2O3为靶材,在MgO(100)基底上制备了Fe3O4薄膜。通过反射高能电子衍射原位观察了薄膜生长前后的表面结构,结果表明所生长的Fe3O4薄膜表面平整。经显微激光拉曼光谱和X光电子能谱分析证实所得薄膜表面成分为纯相Fe3O4。磁电学性能采用多功能物性系统测量,结果表明:当温度降至100 K附近时,薄膜电阻率有较大增加,Verwey相转变的范围变宽而且不明显,说明反向晶粒边界的存在;在7 160 kA.m-1的磁场下,室温磁电阻达到-6.9%,在80和150 K温度下磁电阻分别达到-10.5%和-16.1%;薄膜的室温饱和磁化强度约为260 kA.m-1,其矫顽磁场约为202 kA.m-1。Using sintered a-Fe2O3 as target, Fe3O4 thin films were grown on MgO （100） substrates by laser molecular beam epitaxy. The quality of the films was checked in situ by monitoring reflection high energy electron diffraction patterns during deposition. The results showed that the surface of the films is smooth. Raman spectroscopy and X-ray photoelectron spectroscopy （XPS） analysis confirms the presence of single-phase Fe3O4 in the surface of the films, and no other iron oxides exist. The magnetic and electrical properties of the Fe3O4 thin films were investigated. The results showed that the resistivity of the Fe3O4 thin films increases sharply about 100 K, and the temperature range of Verwey transition broadens unobviously, which implies the existence of the antiphase boundary. At 7 160 kA·m^-1 magnetic field, the magnetic resistivity at 300 K is up to -6.9%, and that at 80 K or 150 K is up to -10.5% or -16.1%, respectively. The saturation magnetization is close to 260 kA·m^-1 at a field of 398 kA·m^-1, and the coercivity is about 202 kA·m^-1.

关 键 词：薄膜 半金属 激光分子束 外延 矫顽磁场 

分 类 号：TM277.4[一般工业技术—材料科学与工程]