Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1526693 | Materials Chemistry and Physics | 2008 | 4 Pages |
Abstract
We present temperature-dependent magneto-optic hysteresis curves of “quasi-two-dimensional” arrays of 10 nm Co nanoparticles which are covered by a native CoO layer. The particles deposited on thin aluminum films become magnetically very hard at 10 K, i.e. the coercive field exceeds 1.6 T. Only in a narrow temperature range near 100 K an out-of-plane magnetization loop with considerable coercivity is observed. A shift of the magneto-optic hysteresis curves due to exchange bias was detected. Magnetization measurements on a frozen volume of nanoparticle solution reveal a strong exchange-bias effect of 0.8 T at 10 K. The exchange-bias effect is attributed to the rough interface and/or spin-disordered state between CoO shell and Co core.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
B. Kalska, P. Fumagalli, M. Hilgendorff, M. Giersig,