Author:

Keywords:

Science & Technology, Technology, Physical Sciences, Materials Science, Multidisciplinary, Physics, Applied, Physics, Condensed Matter, Materials Science, Physics, EXCHANGE BIAS, ANISOTROPIC MAGNETORESISTANCE, BILAYERS, 02 Physical Sciences, 03 Chemical Sciences, 09 Engineering, Fluids & Plasmas, 34 Chemical sciences, 40 Engineering, 51 Physical sciences

Abstract:

© 2014 American Physical Society. We investigated the training effect and magnetization reversal in CoO/Co bilayer films grown epitaxially on MgO (001) substrates. The asymmetry of the magnetization reversal, which appears due to the exchange bias after field cooling, survives after training, in contrast to the case of polycrystalline bilayers. By applying hysteresis loops with the magnetic field perpendicular to the cooling field, we are able to modify the orientation of the average uncompensated magnetization of the antiferromagnetic CoO. Subsequently, the untrained state can be partially restored, and more importantly the magnetization reversal asymmetry can be inverted by starting the perpendicular loop with the appropriate field polarity. Consequently, we succeeded in manipulating the magnetization reversal asymmetry and even in achieving opposite reversal asymmetries in the same exchange bias system.