Magnetic freezing transition in a CoO/Permalloy bilayer revealed by transverse ac susceptibility
arXiv:1807.05990 · doi:10.1016/j.jmmm.2018.12.056
Abstract
We utilize variable-temperature, variable-frequency magneto-optical transverse magnetic susceptibility technique to study the static and dynamical magnetic properties of a thin-film CoO/Permalloy bilayer. Our measurements demonstrate that in the studied system, the directional asymmetry of the hysteresis loop is associated mainly with the difference in the reversal mechanisms between the two reversed states of magnetization stabilized by the exchange-induced uniaxial anisotropy. The latter is found to be much larger than the exchange-induced unidirectional anisotropy of the ferromagnet. We also observe an abrupt variation of the frequency-dependent imaginary part of ac susceptibility near the exchange bias blocking temperature, consistent with the magnetic freezing transition inferred from the previous time-domain studies of magnetic aging in similar systems. The developed measurement approach enables precise characterization of the dynamical and static characteristics of thin-film magnetic heterostructures that can find applications in reconfigurable magnonic and neuromorphic circuits.
arXiv comment13 pages, 7 figures
References in corpus (8)
- Antiferromagnetic spintronics
- Optimization with Extremal Dynamics
- Nonmonotonic Aging and Memory in a Frictional Interface
- Kovacs-like memory effect in driven granular gases
- Random Fields, Topology, and The Imry-Ma Argument
- Effects of Antiferromagnetic Spin Rotation on Anisotropy of Ferromagnetic/Antiferromagnetic Bilayers
- Cooperative Multiscale Aging in a Ferromagnet/Antiferromagnet Bilayer
- Spin glass transition in a thin-film NiO/Permalloy bilayer