Influence of film composition in Co2MnSi electrodes on tunnel magnetoresistance characteristics of Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
Influence of film composition in Co2MnSi electrodes on tunnel magnetoresistance characteristics of Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
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DOI：
10.1063/1.3272926
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发表时间：
2009-12-07
影响因子：
4
通讯作者：
Yamamoto, Masafumi
中科院分区：
文献类型：
--
作者：
Ishikawa, Takayuki;Liu, Hong-xi;Yamamoto, Masafumi
在 Co2Mn α Si 电极中制备了具有不同 Mn 成分 α 值的全外延 Co2MnSi (CMS)/MgO/CMS 磁隧道结 (MTJ)，并研究了 α 对这些 MTJ 隧道磁阻 (TMR) 特性的影响。具有富锰 CMS 电极的 MTJ 显示出 TMR 比率，在 4.2 K 下高达 1135%，在 α = 1.29 的室温下高达 236%，超过了具有几乎化学计量组成的 CMS 电极的 MTJ。 α 超过 1.0 的较高 TMR 比率的一个可能原因是，对于富锰 CMS 电极，由于 Co-Mn 反位点的抑制，导致半金属能隙中费米能级周围存在的能隙态密度降低，其中 Mn 位点被 Co 原子取代。 (C) 2009 年美国物理研究所。 [号码：10.1063/1.3272926]
Fully epitaxial Co2MnSi (CMS)/MgO/CMS magnetic tunnel junctions (MTJs) with various values of Mn composition alpha in Co2Mn alpha Si electrodes were fabricated and the influence of alpha on the tunnel magnetoresistance (TMR) characteristics of these MTJs was investigated. MTJs with Mn-rich CMS electrodes showed TMR ratios, up to 1135% at 4.2 K and 236% at room temperature for alpha = 1.29, exceeding those of MTJs with CMS electrodes having an almost stoichiometric composition. A possible origin of the higher TMR ratios for alpha beyond 1.0 is a decreased density of gap states existing around the Fermi level in the half-metal gap caused by the suppression of Co-Mn antisites, where a Mn site is replaced by a Co atom, for Mn-rich CMS electrodes. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3272926]