Exchange-biased magnetic tunnel junctions with antiferromagnetic ?-Mn3Ga

Abstract

Oriented c-axis films of the hexagonal triangular antiferromagnetic epsilon-Mn3Ga have been used in bottom-pinned synthetic antiferromagnet magnetic tunnel junctions with MgO barriers, which show up to 150% tunneling magnetoresistance at room temperature. Exchange bias fields as high as 150mT can be achieved for samples field-cooled from 100 degrees C. Thin films of the antiferromagnet have a Neel temperature in excess of 650K and provide an interface exchange energy with CoFe of 0.09 mJ m(-2). They show an isotropic uncompensated magnetization of M-s = 48 kA m(-1), with a coercivity mu H-0(c) > 3T. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4768941]