耐高温垂直取向FePt连续薄膜的表面形貌与磁性  

Morphology and magnetic properties of vertically orientated continuous FePt films annealed at high temperature

作　　者：向晖[1] 莫小静[1] 郑远平[1] 吕庆[1] 谭兴文[1] 林跃强[1] 熊祖洪[1] 李国庆[1] 

机构地区：[1]西南大学物理科学与技术学院,重庆400715

出　　处：《科学通报》2011年第15期1188-1195,共8页Chinese Science Bulletin

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

摘　　要：用磁控溅射法在加热到400℃的MgO(001)单晶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,总成分配比为Fe50Pt50.然后对其在[500,900]℃温度范围进行真空热处理,分析了热处理温度对薄膜表面形貌、晶体结构以及磁特性的影响.结果表明,在加热基片上生长的FePt薄膜,层间已经发生扩散,形成无序的A1相.经过700℃以上的高温热处理,薄膜转变为具有(001)织构的L10相FePt合金,易磁化轴沿垂直于膜面的方向,有序度大于0.85,单轴磁晶各向异性能约2.7×107erg/cc.利用扩散后残存的周期性微弱成分起伏,可以使薄膜在800℃以下保持形貌连续.用原子力显微镜对薄膜表面进行观察证实,在780℃进行热处理,薄膜的表面最平整.这种优质的连续薄膜可以应用于微加工制作超高密度垂直磁记录阵列介质.By magnetron sputtering, [Fe（0.6 nm）/Fe305Pt695（1.9 nm）h0 continuous multilayer films with nominal composition of FesoPtso and total thickness of 25 nm were deposited on MgO（001） substrates heated to 400℃, and then subjected to a vacuum annealing at temperatures in the range of Ta = [500, 900]℃. The morphology, crystallography as well as magnetic property dependences of Ta were investigated by scanning electron microscope, atomic force microscope, X-ray diffraction and vibrating sample magnetometer. Heating the substrate during sputtering resulted in interlayer diffusion, and the as-deposited multilayer film showed the soft magnetic behaviors of FePt alloy with disordered A1 phase. Annealed at Ta≥700℃, the film became the ordered L10 phase with significant （001） orientation; the ordering parameter was more than 0.85; the magnetocrystalline anisotropic energy exceeded 2.7x107 erg/cc. Due to the residual subtle periodical compositional fluctuation in the film, the ordering could nucleate interior the film and the Pt-enrichment boundaries were sufficiently suppressed. The continuity of morphology was maintained at Ta〈800~C. The observation by atomic force microscope indicated that the film annealed at Ta = 780~C had the flattest surface with sparse swells lower than 3 nm. This kind of heat-resisting continuous film would fit the need for microfabrication of patterned arrays of L10 FePt for applications such as the perpendicular magnetic recording media.

关 键 词：L10相FePt 连续薄膜 热处理 表面形貌 磁性 

分 类 号：O484.43[理学—固体物理]