Articles in peer-reviewed journals
|Exchange bias phenomena in ferrimagnetic based bilayers|
|Canet F., Mangin S., Bellouard C., Piecuch M., Schuhl A.|
|Journal of Applied Physics 89 (2001) 6916|
|DOI : 10.1063/1.1357148|
We present positive and negative exchange bias (EB) phenomena observed in two ferrimagnetic-based amorphous bilayers systems: FeSn/FeGd and FeGd/TbFe. In both cases, magnetization measurements exhibit a shift of the loop of one of the ferrimagnetic layer towards a positive or negative field. In FeSn/FeGd, the coupling at the interface between the net magnetization of the two layers is antiferromagnetic, which leads to a positive shift. However in FeGd/TbFe bilayers, the coupling is ferromagnetic and the shift is negative. The EB phenomenon is attributed to the occurrence of a magnetic domain wall present at the interface, which can be "compressed" or "decompressed" by an external applied field. A simple model based on the competition between the Zeeman energy and the interface exchange interaction energy permits a good quantitative evaluation of the observed EB fields.