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Title: Magnetic and electrical properties of Fe/Si core-shell cluster assemblies prepared with double-glow-discharge sources

Abstract

Using a double glow-discharge-cluster-source-system, in which one glow discharge is a dc mode and the other an rf discharge mode, Fe and Si clusters have been produced independently and deposited simultaneously on a substrate. When a separation plate is not inserted between two glow-discharge chambers, core-shell clusters are obtained: An Fe core is surrounded by small Si crystallites. The magnetization measurement indicates that the magnetic coercive force of the Fe/Si core-shell cluster assembly is much smaller than those of Fe cluster assemblies at low temperature and no shift of the field-cooled hysteresis loop related to the zero-field-cooled loop is detected, probably because Si shells prevent Fe cluster surfaces from their oxidation. The temperature dependence of electrical resistance is attributed to electron conduction via Si shell networks above 180 K, while it is attributed to variable range electron conduction between Fe clusters.

Authors:
; ; ;  [1]
  1. Department of Materials Science and Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan)
Publication Date:
OSTI Identifier:
20706504
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 87; Journal Issue: 25; Other Information: DOI: 10.1063/1.2149972; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; COERCIVE FORCE; ELECTRIC CONDUCTIVITY; EVAPORATION; FERMI LEVEL; FERROMAGNETIC MATERIALS; GLOW DISCHARGES; HYSTERESIS; IRON; MAGNETIZATION; OXIDATION; SEMICONDUCTOR MATERIALS; SILICON; SUBSTRATES; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0065-0273 K

Citation Formats

Katoh, R., Hihara, T., Peng, D.L., and Sumiyama, K. Magnetic and electrical properties of Fe/Si core-shell cluster assemblies prepared with double-glow-discharge sources. United States: N. p., 2005. Web. doi:10.1063/1.2149972.
Katoh, R., Hihara, T., Peng, D.L., & Sumiyama, K. Magnetic and electrical properties of Fe/Si core-shell cluster assemblies prepared with double-glow-discharge sources. United States. doi:10.1063/1.2149972.
Katoh, R., Hihara, T., Peng, D.L., and Sumiyama, K. Mon . "Magnetic and electrical properties of Fe/Si core-shell cluster assemblies prepared with double-glow-discharge sources". United States. doi:10.1063/1.2149972.
@article{osti_20706504,
title = {Magnetic and electrical properties of Fe/Si core-shell cluster assemblies prepared with double-glow-discharge sources},
author = {Katoh, R. and Hihara, T. and Peng, D.L. and Sumiyama, K.},
abstractNote = {Using a double glow-discharge-cluster-source-system, in which one glow discharge is a dc mode and the other an rf discharge mode, Fe and Si clusters have been produced independently and deposited simultaneously on a substrate. When a separation plate is not inserted between two glow-discharge chambers, core-shell clusters are obtained: An Fe core is surrounded by small Si crystallites. The magnetization measurement indicates that the magnetic coercive force of the Fe/Si core-shell cluster assembly is much smaller than those of Fe cluster assemblies at low temperature and no shift of the field-cooled hysteresis loop related to the zero-field-cooled loop is detected, probably because Si shells prevent Fe cluster surfaces from their oxidation. The temperature dependence of electrical resistance is attributed to electron conduction via Si shell networks above 180 K, while it is attributed to variable range electron conduction between Fe clusters.},
doi = {10.1063/1.2149972},
journal = {Applied Physics Letters},
number = 25,
volume = 87,
place = {United States},
year = {Mon Dec 19 00:00:00 EST 2005},
month = {Mon Dec 19 00:00:00 EST 2005}
}
  • Using a double-glow-discharge-cluster-source system, in which one glow discharge was a dc mode and the other an rf discharge mode, Co and Si clusters were independently produced and simultaneously deposited on a substrate. When a separation plate was inserted between two glow-discharge chambers, a mixture of Co and Si clusters was obtained: small Co clusters were distributed at random, while the Si clusters were aggregated to form large secondary particles. Without inserting the separation plate, on the other hand, core-shell clusters were obtained: a Co core was surrounded by small Si crystallites. The magnetization measurement indicated that the magnetic coercivemore » force of Co/Si core-shell cluster assemblies was much smaller than that of Co cluster assemblies in which Co clusters were covered with antiferromagnetic CoO shells, indicating that the Si shell prevented Co cluster surfaces from their oxidation. Therefore, the present double-cluster-source system is useful in fabricating various sorts of cluster composites, which cannot be prepared by conventional coevaporation or precipitation methods.« less
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