Large and Robust Exchange Bias in Co/CoO film: Implication for Flexible Spintronics

Abstract

Abstract Developing a robust and flexible exchange bias (EB) system is crucial for wearable spintronic devices. In this work, large and robust EB effect is demonstrated in flexible Co/CoO thin films grown by magnetron sputtering. The obtained EB field is as large as 6172 Oe at low temperatures on a flexible substrate. Based on the atomistic spin models, the unexpectedly large EB field is explained by the decrease of ferromagnetic grain size and the increase of ferromagnetic /antiferromagnetic contact area. Furthermore, the strain‐dependent coercivity and EB effect are observed in flexible Co/CoO films. Finally, the flexible Co/CoO thin film shows no degradation (even a slight increase) of performances in all figures of merit after 500 bending cycles, indicating excellent mechanical durability. This study sheds light on Co/CoO as a robust EB material for flexible spintronics.

Keywords

• Co/CoO
• exchange bias
• Ferromagnetic /antiferromagnetic film
• flexible spintronics
• magnetism