Improved tunneling magnetoresistance in interface engineered (La,Sr)MnO3 junctions
Improved tunneling magnetoresistance in interface engineered (La,Sr)MnO3 junctions
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DOI：
10.1063/1.2245442
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发表时间：
2006-07
影响因子：
4
通讯作者：
Y. Ishii;H. Yamada;Hiromi Sato;H. Akoh;Y. Ogawa;M. Kawasaki;Y. Tokura
中科院分区：
文献类型：
--
作者：
Y. Ishii;H. Yamada;Hiromi Sato;H. Akoh;Y. Ogawa;M. Kawasaki;Y. Tokura
采用（La，Sr）MnO3（LSMO）作为铁磁电极，制备了具有不同绝缘势垒和界面结构的自旋隧道结. LaAlO3势垒结的隧道磁电阻（TMR）比SrTiO3势垒结的隧道磁电阻（TMR）大230%（10K）。当两个未掺杂的LaMnO3的单元电池插入LSMO和SrTiO 3之间的两个界面的SrTiO 3势垒结，TMR也显着提高到170%。这些结果，包括TMR的温度依赖性，定性地同意在界面处的局部磁化的特性，通过磁化诱导的二次谐波产生（MSHG）的相应的接口结构进行评估。然而，轻微的偏差出现作为一个系统的抑制TMR的所有结在高温下相比，MSHG的结果。此外，TMR的结果似乎是更多的退化比MSHG的SrTiO 3势垒结的结果。...
Spin tunnel junctions were fabricated and characterized with various insulating barriers and interface structures employing (La,Sr)MnO3 (LSMO) as the ferromagnetic electrodes. Junctions with LaAlO3 barriers exhibited systematically larger tunnel magnetoresistance (TMR) (TMR ratio ∼230% at 10K) than those with SrTiO3 barriers (∼50%). When two unit cells of nondoped LaMnO3 are inserted between LSMO and SrTiO3 at both interfaces in the SrTiO3-barrier junction, the TMR was also significantly enhanced to ∼170%. These results, including the temperature dependence of TMR, qualitatively agree with the characteristics of the local magnetization at the interface that was evaluated by magnetization-induced second harmonic generation (MSHG) for the corresponding interface structures. However, slight deviations appear as a systematic suppression of TMR for all the junctions at high temperatures compared with MSHG results. Also, TMR results appear to be more degraded than MSHG results for the SrTiO3-barrier junctions. ...