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Title: Optimization of permanent magnetic properties in melt spun Co{sub 82−x}Hf{sub 12+x}B{sub 6} (x = 0–4) nanocomposites

Abstract

Magnetic properties of melt spun Co{sub 82−x}Hf{sub 12+x}B{sub 6} ribbons made with various wheel speeds have been studied. The ribbons with x = 0–1 are not easy to crystallize and thus display soft magnetic behavior even at wheel speed of 10 m/s. In contrast, the ribbons with x = 1.5–4 at optimized wheel speed exhibit good permanent magnetic properties of B{sub r} = 0.41–0.59 T, {sub i}H{sub c} = 120–400 kA/m, and (BH){sub max} = 10.6–48.1 kJ/m{sup 3}. The optimal magnetic properties of B{sub r} = 0.59 T, {sub i}H{sub c} = 384 kA/m, and (BH){sub max} = 48.1 kJ/m{sup 3} are achieved for Co{sub 80}Hf{sub 14}B{sub 6} ribbons at wheel speed of 30 m/s. X-ray diffraction, thermo-magnetic analysis, and transmission electron microscopy results show that good hard magnetic properties of Co{sub 82−x}Hf{sub 12+x}B{sub 6} ribbons (x = 2–4) are originated from the Co{sub 11}Hf{sub 2} phase well coupled with the Co phase. The change of magnetic properties for Co{sub 82−x}Hf{sub 12+x}B{sub 6} ribbons spun at various wheel speeds is correlated to microstructure and phase constitution. The strong exchange-coupling effect between magnetic grains for the ribbons with x = 2–3 at wheel speed = 30 m/s leads to remarkable permanent magnetic properties. The presented results suggest that the optimized Co{sub 82−x}Hf{sub 12+x}B{sub 6} (x = 2–3) ribbons are much suitable than others (x = 0–1.5 and 4) for making rare earth and Pt-free magnets.

Authors:
 [1]; ; ;  [2];  [3]
  1. Department of Applied Physics, Tunghai University, Taichung 407, Taiwan (China)
  2. Department of Physics, National Chung Cheng University, Chia-Yi 621, Taiwan (China)
  3. Superrite Electronics Co. Ltd., Taipei 111, Taiwan (China)
Publication Date:
OSTI Identifier:
22409922
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 117; Journal Issue: 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; BORON ALLOYS; COBALT BASE ALLOYS; COUPLING; HAFNIUM ALLOYS; MAGNETIC MATERIALS; MAGNETIC PROPERTIES; MICROSTRUCTURE; NANOCOMPOSITES; OPTIMIZATION; THERMOMAGNETISM; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION

Citation Formats

Chang, H. W., Liao, M. C., Shih, C. W., Chang, W. C., E-mail: phywcc@ccu.edu.tw, and Shaw, C. C. Optimization of permanent magnetic properties in melt spun Co{sub 82−x}Hf{sub 12+x}B{sub 6} (x = 0–4) nanocomposites. United States: N. p., 2015. Web. doi:10.1063/1.4913896.
Chang, H. W., Liao, M. C., Shih, C. W., Chang, W. C., E-mail: phywcc@ccu.edu.tw, & Shaw, C. C. Optimization of permanent magnetic properties in melt spun Co{sub 82−x}Hf{sub 12+x}B{sub 6} (x = 0–4) nanocomposites. United States. doi:10.1063/1.4913896.
Chang, H. W., Liao, M. C., Shih, C. W., Chang, W. C., E-mail: phywcc@ccu.edu.tw, and Shaw, C. C. Thu . "Optimization of permanent magnetic properties in melt spun Co{sub 82−x}Hf{sub 12+x}B{sub 6} (x = 0–4) nanocomposites". United States. doi:10.1063/1.4913896.
@article{osti_22409922,
title = {Optimization of permanent magnetic properties in melt spun Co{sub 82−x}Hf{sub 12+x}B{sub 6} (x = 0–4) nanocomposites},
author = {Chang, H. W. and Liao, M. C. and Shih, C. W. and Chang, W. C., E-mail: phywcc@ccu.edu.tw and Shaw, C. C.},
abstractNote = {Magnetic properties of melt spun Co{sub 82−x}Hf{sub 12+x}B{sub 6} ribbons made with various wheel speeds have been studied. The ribbons with x = 0–1 are not easy to crystallize and thus display soft magnetic behavior even at wheel speed of 10 m/s. In contrast, the ribbons with x = 1.5–4 at optimized wheel speed exhibit good permanent magnetic properties of B{sub r} = 0.41–0.59 T, {sub i}H{sub c} = 120–400 kA/m, and (BH){sub max} = 10.6–48.1 kJ/m{sup 3}. The optimal magnetic properties of B{sub r} = 0.59 T, {sub i}H{sub c} = 384 kA/m, and (BH){sub max} = 48.1 kJ/m{sup 3} are achieved for Co{sub 80}Hf{sub 14}B{sub 6} ribbons at wheel speed of 30 m/s. X-ray diffraction, thermo-magnetic analysis, and transmission electron microscopy results show that good hard magnetic properties of Co{sub 82−x}Hf{sub 12+x}B{sub 6} ribbons (x = 2–4) are originated from the Co{sub 11}Hf{sub 2} phase well coupled with the Co phase. The change of magnetic properties for Co{sub 82−x}Hf{sub 12+x}B{sub 6} ribbons spun at various wheel speeds is correlated to microstructure and phase constitution. The strong exchange-coupling effect between magnetic grains for the ribbons with x = 2–3 at wheel speed = 30 m/s leads to remarkable permanent magnetic properties. The presented results suggest that the optimized Co{sub 82−x}Hf{sub 12+x}B{sub 6} (x = 2–3) ribbons are much suitable than others (x = 0–1.5 and 4) for making rare earth and Pt-free magnets.},
doi = {10.1063/1.4913896},
journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 17,
volume = 117,
place = {United States},
year = {2015},
month = {5}
}