Exchange bias effect of epitaxial noncollinear antiferromagnetic Mn3Sn films

The exchange bias effect resulting from antiferromagnetic materials plays a crucial role in spintronics devices. This effect can effectively fix the orientation of magnetization at the interface and is essential for magnetization control and switching behavior. Noncollinear antiferromagnetic materials have recently received much attention due to their novel physical properties. Here, we investigate the exchange bias effect in the noncollinear antiferromagnetic Mn3Sn/Py bilayers. It indicates the exchange bias and blocking temperature is directly related to the surface roughness and thickness of the noncollinear antiferromagnetic layer. By optimizing the thickness and deposition temperature, we achieve an exchange bias of 538 Oe at 5 K and a blocking temperature of 280 K, which is much larger than the previous works reported for hexagonal non-antiferromagnets. Our work provides a solid foundation for understanding the exchange bias of ferromagnetic/noncollinear antiferromagnetic bilayers, and we demonstrate the potential of Mn3Sn with unique exchange bias properties, which may contribute to the future design and construction of advanced antiferromagnetic spintronic devices.