標題: Direct observation of rotatable uncompensated spins in the exchange bias system Co/CoO-MgO
作者: Ge, Chuannan
Wan, Xiangang
Pellegrin, Eric
Hu, Zhiwei
Valvidares, S. Manuel
Barla, Alessandro
Liang, Wen-I.
Chu, Ying-Hao
Zou, Wenqin
Du, Youwei
材料科學與工程學系
Department of Materials Science and Engineering
公開日期: 2013
摘要: We have observed a large exchange bias field H-E approximate to 2460 Oe and a large coercive field H-C approximate to 6200 Oe at T = 2 K for Co/CoO core-shell nanoparticles (similar to 4 nm diameter Co metal core and CoO shell with similar to 1 nm thickness) embedded in a non-magnetic MgO matrix. Our results are in sharp contrast to the small exchange bias and coercive field in the case of a non-magnetic Al2O3 or C matrix materials reported in previous studies. Using soft X-ray magnetic circular dichroism at the Co-L-2,L-3 edge, we have observed a ferromagnetic signal originating from the antiferromagnetic CoO shell. This gives direct evidence for the existence of rotatable interfacial uncompensated Co spins in the nominally antiferromagnetic CoO shell, thus supporting the uncompensated spin model as a microscopic description of the exchange bias mechanism.
URI: http://hdl.handle.net/11536/22911
http://dx.doi.org/10.1039/c3nr02013d
ISSN: 2040-3364
DOI: 10.1039/c3nr02013d
期刊: NANOSCALE
Volume: 5
Issue: 21
起始頁: 10236
結束頁: 10241
顯示於類別:期刊論文


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