在MgO(001)基板上生长连续的L1_0-FePt纳米薄膜  

Growth of continuous L1_0-FePt films on MgO(001) substrates

作　　者：莫小静[1] 向晖[1] 郑远平[1] 李国庆[1] 熊祖洪[1] 屿敏之 

机构地区：[1]西南大学物理科学与技术学院,重庆400715 [2]东北学院大学工学部

出　　处：《中国科学：物理学、力学、天文学》2011年第1期78-85,共8页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(批准号:51071132);重庆市自然科学基金(编号:CSTC2009BB8102);中央高校基本科研业务费专项资金(编号:XDJK2009C193)资助项目

摘　　要：用磁控溅射法在加热到400℃的MgO(001)基片上沉积了总厚度为25nm的[Fe(0.6nm)/Fe30.5Pt69.5(1.9nm)]10多层连续薄膜,并对其在[500,900]℃的温度范围进行了3h的真空热处理.结果表明,薄膜在沉积过程中发生了层间扩散,形成A1相的FePt合金,表现为软磁特性;热处理温度高于700℃时,薄膜内形成L10相的(001)织构,其单轴磁晶各向异性能高于2.5×107ergcc?1;薄膜能在800℃以下保持形貌连续.借助于半导体载流子扩散和复合模型,对薄膜在高温下形貌保持连续的机理进行了探讨.分析认为,虽然薄膜在沉积过程中发生了层间扩散,但内部仍然残存微弱的周期性成分起伏,这可以有效阻碍热处理过程中因相变而引起的Pt元素析出,从而抑制了因形成富Pt晶界而导致的形貌不连续.这种薄膜可以方便地用于微加工制作磁性阵列和隧道结.[Fe（0.6 nm）/Fe30.5Pt69.5（1.9 nm）]10 multilayer films with total thickness of 25 nm were deposited on MgO（001） substrates heated to 400°C by DC magnetron sputtering, and were subsequently subjected to a vacuum annealing for 3 h at temperatures in the range of [500, 900]°C. The as-deposited films had a soft magnetic A1 phase due to interlayer diffusion. Significant （001） texture of L10 phase was achieved by annealing the film at or over 700°C, with magnetocrystalline anisotropic energy exceeding 2.5×107 erg cc？1. The film morphology kept continuous till the annealing temperature was as high as 800°C. A modified diffusion-recombination model of carrier was adopted to discuss the morphology continuity of FePt film in high temperature environment. The slight compositional gradient in the film after interlayer diffusion might suppress the segregation of Pt and sufficiently prevented from the Pt enrichment which would result in the discontinuous boundaries. This kind of continuous L10 FePt film with preferential crystallographic orientation can be used conveniently for microfabrication of patterned arrays and magnetic tunnel junctions.

关 键 词：L10-FePt连续薄膜 周期性成分起伏 Pt富集 相变 热处理 

分 类 号：O484[理学—固体物理]