@article{e17e2631cbcb4a1c81d1f189bfe85f51,
title = "Proteresis in Co:CoO core-shell nanoclusters",
abstract = "The magnetism of ultrasmall Co:CoO core-shell nanoclusters is investigated. The structures, produced by cluster-beam deposition, have Co core sizes ranging from 1 to 7 nm and a CoO shell thickness of about 3 nm. Hysteresis loops as well as zero-field-cooled and field-cooled magnetization curves have been measured and a striking feature of the nanostructures is the existence of proteretic (clockwise) rather than hysteretic loops in the core-size range from 3 to 4 nm. The proteretic behavior and its particle-size dependence reflect a subtle interplay between various anisotropies and exchange interactions in the Co and CoO phases and at the Co-CoO interface.",
author = "Wei, {X. H.} and R. Skomski and Sun, {Z. G.} and Sellmyer, {D. J.}",
note = "Funding Information: This research is supported by NSF MRSEC under Grant No. 0213808 and NCMN. FIG. 1. Geometry of CoO:Co core-shell nanostructures: (a) pseudomultilayer and (b) core-shell particle with A and B showing sublattice magnetizations in CoO. FIG. 2. TEM image of core-shell clusters having a CoO shell thickness of 3 nm and Co core diameters of 7 nm . FIG. 3. Blocking behavior of the core-shell structures: (a) ZFC and FC magnetization curves for 7 nm clusters, and (b) blocking temperature T p as a function of core diameter. The solid curve in (b) is a model prediction. FIG. 4. Magnetization curves for (a) D = 1 nm (hysteresis) and (b) D = 3 nm (proteresis). FIG. 5. Temperature dependence of hysteresis loops (a) and vertical shifts (b) of compact films. ",
year = "2008",
doi = "10.1063/1.2829239",
language = "English (US)",
volume = "103",
journal = "Journal of Applied Physics",
issn = "0021-8979",
publisher = "American Institute of Physics",
number = "7",
}