Coercivity enhancement in exchange biased CoO/Co3Pt bilayers

T Kosub (1) , C Schubert (1) , H Schletter (1) , M Daniel (1) , M Hietschold (1) , V Neu , M Maret (2) , D Makarov (1) , M Albrecht

1 Institute of Physics
2 SIMaP - Science et Ingénierie des Matériaux et Procédés

A study on the exchange bias effect in an hcp (0002)-textured Co 3 Pt alloy film biased by a thin CoO film is presented. The Co 3 Pt film reveals an out-of-plane easy axis of magnetization although it was grown on an amorphous silica substrate at room temperature. Similar exchange bias fields measured in in-plane and out-of-plane directions of the CoO/Co 3 Pt bilayer system were observed for maximum cooling field. Whereas a pronounced cooling field dependence of the exchange bias field is observed in-plane, it remains constant in out-of-plane direction. The temperature evolution of the coercivity and the shift of the hysteresis loop caused by the exchange bias effect are discussed in terms of thermal activation accounting for the temperature dependent competition between the interfacial exchange energy and the anisotropy energy of antiferromagnetic grains.

Mots clés: Physical Sciences

Domaines: Matériaux

T Kosub, C Schubert, H Schletter, M Daniel, M Hietschold, et al.. Coercivity enhancement in exchange biased CoO/Co3Pt bilayers. Journal of Physics D: Applied Physics, 2011, 44 (1), pp.15002. ⟨10.1088/0022-3727/44/1/015002⟩. ⟨hal-00585171⟩