Exchange bias in reduced dimensions: cobalt nanocluster arrays under the influence of nanometer thin MnPt capping layers

0432638 - FZÚ 2015 RIV US eng J - Článek v odborném periodiku
Sessi, V. - Hertenberger, S. - Zhang, J. - Schmitz, D. - Gsell, S. - Schreck, M. - Morel, R. - Brenac, A. - Honolka, Jan - Kern, K.
Exchange bias in reduced dimensions: cobalt nanocluster arrays under the influence of nanometer thin MnPt capping layers.
Journal of Applied Physics. Roč. 113, č. 12 (2014), s. 1-10, č. článku 123903. ISSN 0021-8979. E-ISSN 1089-7550
Institucionální podpora: RVO:68378271
Klíčová slova: antiferromagnetism * cobalt * nanoclusters * quenching * superparamagnetism
Obor OECD: Condensed matter physics (including formerly solid state physics, supercond.)
Impakt faktor: 2.183, rok: 2014

The magnetic behavior of cobalt nanocluster arrays arranged on a boron-nitride nanomesh and capped with MnPt layers of varying thickness θ MnPt is investigated. The magnetic properties of the arrays are found to be strongly dependent on the cobalt nanocluster size: large 3-dimensional clusters of several nanometers size under the influence of only θ MnPt 5nm exhibit prototypical exchange bias behavior, whereas small 2-dimensional clusters of about 1nm in diameter show superparamagnetic behavior, however, with a strong quenching of the average cobalt magnetization. The latter effect is correlated with the formation of a stable antiferromagnetic phase at increasing θMnPt and is discussed in terms of the domain state exchange bias model. The quenching suggests either partial antiferromagnetic alignment of cobalt spins within a cluster or a random orientation of cobalt cluster macrospins with respect to each other.
Trvalý link: http://hdl.handle.net/11104/0237017