dorsal/arxiv
View SchemaMagnetic structure of free cobalt clusters studied with Stern-Gerlach deflection experiments
| Authors | F. W. Payne, Wei Jiang, J. W. Emmert, Jun Deng, L. A. Bloomfield |
|---|---|
| Categories | |
| ArXiv ID | physics/0610055 |
| URL | https://arxiv.org/abs/physics/0610055 |
| DOI | 10.1103/PhysRevB.75.094431 |
Abstract
We have studied the magnetic properties of free cobalt clusters in two semi-independent Stern-Gerlach deflection experiments at temperatures between 60 and 307 K. We find that clusters consisting of 13 to 200 cobalt atoms exhibit behavior that is entirely consistent with superparamagnetism, though complicated by finite-system fluctuations in cluster temperature. By fitting the data to the Langevin function, we report magnetic moments per atom for each cobalt cluster size and compare the results of our two measurements and all those performed previously. In addition to a gradual decrease in moment per atom with increasing size, there are oscillations that appear to be caused by geometrical shell structure. We discuss our observations in light of the two competing models for Langevin-like magnetization behavior in free clusters, superparamagnetism and adiabatic magnetization, and conclude that the evidence strongly supports the superparamagnetic model.
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"abstract": "We have studied the magnetic properties of free cobalt clusters in two\nsemi-independent Stern-Gerlach deflection experiments at temperatures between\n60 and 307 K. We find that clusters consisting of 13 to 200 cobalt atoms\nexhibit behavior that is entirely consistent with superparamagnetism, though\ncomplicated by finite-system fluctuations in cluster temperature. By fitting\nthe data to the Langevin function, we report magnetic moments per atom for each\ncobalt cluster size and compare the results of our two measurements and all\nthose performed previously. In addition to a gradual decrease in moment per\natom with increasing size, there are oscillations that appear to be caused by\ngeometrical shell structure. We discuss our observations in light of the two\ncompeting models for Langevin-like magnetization behavior in free clusters,\nsuperparamagnetism and adiabatic magnetization, and conclude that the evidence\nstrongly supports the superparamagnetic model.",
"arxiv_id": "physics/0610055",
"authors": [
"F. W. Payne",
"Wei Jiang",
"J. W. Emmert",
"Jun Deng",
"L. A. Bloomfield"
],
"categories": [
"physics.atm-clus"
],
"doi": "10.1103/PhysRevB.75.094431",
"title": "Magnetic structure of free cobalt clusters studied with Stern-Gerlach deflection experiments",
"url": "https://arxiv.org/abs/physics/0610055"
},
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