Wang YY, Song C, Cui B, Wang GY, Zeng F, Pan F. Room-temperature perpendicular exchange coupling and tunneling anisotropic magnetoresistance in an antiferromagnet-based tunnel junction.
PHYSICAL REVIEW LETTERS 2012;
109:137201. [PMID:
23030116 DOI:
10.1103/physrevlett.109.137201]
[Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Indexed: 06/01/2023]
Abstract
We investigate the exchange coupling between perpendicular anisotropy (PMA) Co/Pt and IrMn in-plane antiferromagnets (AFMs), as well as tunneling anisotropic magnetoresistance (TAMR) in [Pt/Co]/IrMn/AlO_{x}/Pt tunnel junctions, where Co/Pt magnetization drives rotation of AFM moments with the formation of exchange-spring twisting. When coupled with a PMA ferromagnet, the AFM moments partially rotate with out-of-plane magnetic fields, in contrast with being pinned along the easy direction of IrMn for in-plane fields. Because of the superior thermal tolerance of perpendicular exchange coupling and the stability of moments in ~6 nm-thick IrMn, TAMR gets significantly enhanced up to room temperature. Their use would advance the process towards practical AFM spintronics.
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