【摘要】 用等离子体氧化形成中间绝缘层的方法可重复制备出具有隧道磁电阻（ＴＭＲ） 效应的Ｎｉ８０Ｆｅ２０／Ａｌ２Ｏ３／Ｃｏ 磁性隧道结．光透射谱等实验结果表明等离子体氧化能可控制地制备较致密的Ａｌ２Ｏ３ 绝缘层．样品的ＴＭＲ 比值在室温下最高可达６－０ ％ ，反转场可低于８００ Ａ／ｍ ，相应的平台宽度约为２４００ Ａ／ｍ ．结电阻Ｒｊ 的变化范围从几百欧到几百千欧，并且ＴＭＲ 比值随零磁场结偏压增大单调减小．更多还原

【Abstract】 With plasma oxidization to create an insulating layer of Al 2O 3,we have repeatedly fabricated some Ni 80 Fe 20 /Al 2O 3/Co magnetic tunnel junctions (MTJ),which show obvious tunneling magnetoresistance (TMR) effect.The insulating layer is well formed by the oxidization procedure,which is verified by optical spectra and other measurement results.At room temperature,the maximum TMR ratio reaches 6 0%.The switch field can be less than 800?A/m and the relative step width is about 2400?A/m.The junction resistance R j changes from hundreds of ohms to hundreds of kilohms and TMR ratio decreases monotonously with the increase of applied junction voltage bias (under zero magnetic field).更多还原