BaTiO_3/CoFe_2O_4/BaTiO_3复合磁电薄膜生长及应力研究  

Growth and Interfacial Strain of BaTiO_3/CoFe_2O_4/BaTiO_3 Magnetoelectric Multilayers

作　　者：周立勋[1] 朱俊[1] 黄文[1] 张鹰[1] 李言荣[1] 罗文博[1] 

机构地区：[1]电子科技大学电子薄膜与集成器件国家重点实验室,成都610054

出　　处：《真空科学与技术学报》2007年第5期386-390,共5页Chinese Journal of Vacuum Science and Technology

基　　金：杰出青年基金资助项目(No.50425207)

摘　　要：用激光分子束外延(LMBE)设备,在SrTiO3(001)基片上外延生长BaTiO3/CoFe2O4/BaTiO3多层复合磁电薄膜结构。通过反射式高能电子衍射(RHEED)对薄膜生长过程进行原位监测,结果显示,随着CoFe2O4厚度的增加薄膜内应力逐渐被释放,并且应力释放的过程导致了薄膜生长模式的变化。高分辨X射线衍射(XRD)发现,随着CoFe2O4厚度的增加,CoFe2O4对BaTiO3薄膜的张应力逐渐增大,BaTiO3晶胞的c轴晶格常数逐渐变小。理论计算给出了BaTiO3面外晶格常数c随CoFe2O4沉积时间的变化规律。原子力显微镜(AFM)对表面形貌进行表征,进一步证明了复合薄膜生长模式的变化。Growth of BaTiO3/CoFe2O4/BaTiO3 magnetoelectric mulfilayers on SrTiO3 substrate by laser molecular beam epitaxy（LMBE） was monitored in-situ with reflection high energy electron diffraction（RHEED）. The micmstmctures of the multilayer were characterized with high resolution X-ray diffraction（XRD） and atomic force microscopy（AFM）. The results show that as the thickness of CoFe2O4 layer increases, the interfacial stress gradually relaxes, resulting in changes of film growth mode;in contrast, the strain on BaTiO3 exerted by CoFe2O4 slowly increases,leading to a shrink of c-axis of the BaTiO3 unit cell. The variations in the c-axis with deposition time of CoFe2O4 were also calculated. AFM images confirm the change in the growth mode.

关 键 词：磁电薄膜 界面应力 RHEED 生长模式 

分 类 号：O484.1[理学—固体物理] O484.2[理学—物理]