Tunnel magnetoresistance in alumina, magnesia and composite tunnel barrier magnetic tunnel junctions

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:323

Article

Schebaum, Oliver¹  Drewello, Volker¹  Auge, Alexander¹  Reiss, Guenter¹  Muenzenberg, Markus^2,3  Schuhmann, Henning^2,3  Seibt, Michael^2,3  Thomas, Andy¹ 

[1] Univ Bielefeld, D-4800 Bielefeld, Germany

[2] Univ Gottingen, Inst Phys 1, D-3400 Gottingen, Germany

[3] Univ Gottingen, Inst Phys 4, D-3400 Gottingen, Germany

关键词: Magnetic tunnel junction;    Tunnel magnetoresistance;    MgO;    Alumina;   

DOI  :  10.1016/j.jmmm.2011.01.011

来源: Elsevier

【 摘 要 】

Using magnetron sputtering, we have prepared Co-Fe-B/tunnel barrier/Co-Fe-B magnetic tunnel junctions with tunnel barriers consisting of alumina, magnesia, and magnesia-alumina bilayer systems. The highest tunnel magnetoresistance ratios we found were 73% for alumina and 323% for magnesia-based tunnel junctions. Additionally, tunnel junctions with a unified layer stack were prepared for the three different barriers. In these systems, the tunnel magnetoresistance ratios at optimum annealing temperatures were found to be 65% for alumina, 173% for magnesia, and 78% for the composite tunnel barriers. The similar tunnel magnetoresistance ratios of the tunnel junctions containing alumina provide evidence that coherent tunneling is suppressed by the alumina layer in the composite tunnel barrier. (C) 2011 Elsevier B.V. All rights reserved.

【 授权许可】

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