Evidence for Core-Shell Magnetic Behavior in Antiferromagnetic Co_3O_4 Nanowires

摘要

Employing magnetometry measurements, we have studied Co_3O_4 nanowires focusing on the core-shell behavior. We find two magnetic contributions, i.e., a regular antiferromagnetic and an additional irreversible one. The first contribution can be attributed to the antiferromagnetically ordered wire cores. The nature of the second one can be identified using thermoremanent and isothermoremanent magnet-izaton curves as magnetic fingerprints of the irreversible magnetization. We conclude that the nanowire shell behaves like a two-dimensional diluted antiferromagnet in a field.