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Title: The distribution alloying elements in alnico 8 and 9 magnets: Site preference of ternary Ti, Fe, Co, and Ni additions in DO{sub 3} Fe{sub 3}Al, Co{sub 3}Al, and Ni{sub 3}Al based intermetallic phases

Abstract

Recently, interest in alnico magnetic alloys has been rekindled due to their potential to substitute for rare-earth based permanent magnets provided modest improvements in their coercivity can be achieved without loss of saturation magnetization. Recent experimental studies have indicated that atomic and magnetic structure of the two phases (one AlNi-based, the other FeCo-based) that comprise these spinodally decomposed alloy is not as simple as previously thought. A key issue that arises is the distribution of Fe, Co, and Ti within the AlNi-based matrix phase. In this paper, we report the results of first-principles calculations of the site preference of ternary alloying additions in DO{sub 3} Fe{sub 3}Al, Co{sub 3}Al, and Ni{sub 3}Al alloys, as models for the aluminide phase. For compound compositions that are Al rich, which correspond to experimental situation, Ti and Fe are found to occupy the α sites, while Co and Ni prefer the γ sites of the DO{sub 3} lattice. An important finding is that the magnetic moments of transition metals in Fe{sub 3}Al and Co{sub 3}Al are ordered ferromagnetically, whereas the Ni{sub 3}Al were found to be nonmagnetic unless the Fe or Co is added as a ternary element.

Authors:
;  [1];  [2]
  1. Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
  2. Wigner Research Centre for Physics, Hungarian Academy of Sciences, Konkoly-Thege M. út 29-33, H-1121 Budapest (Hungary)
Publication Date:
OSTI Identifier:
22402592
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 116; Journal Issue: 17; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALLOYS; COERCIVE FORCE; DISTRIBUTION; MAGNETIC MOMENTS; MAGNETIZATION; PERMANENT MAGNETS; RARE EARTHS; SATURATION; TRANSITION ELEMENTS

Citation Formats

Samolyuk, G. D., Stocks, G. M., and Újfalussy, B. The distribution alloying elements in alnico 8 and 9 magnets: Site preference of ternary Ti, Fe, Co, and Ni additions in DO{sub 3} Fe{sub 3}Al, Co{sub 3}Al, and Ni{sub 3}Al based intermetallic phases. United States: N. p., 2014. Web. doi:10.1063/1.4901229.
Samolyuk, G. D., Stocks, G. M., & Újfalussy, B. The distribution alloying elements in alnico 8 and 9 magnets: Site preference of ternary Ti, Fe, Co, and Ni additions in DO{sub 3} Fe{sub 3}Al, Co{sub 3}Al, and Ni{sub 3}Al based intermetallic phases. United States. https://doi.org/10.1063/1.4901229
Samolyuk, G. D., Stocks, G. M., and Újfalussy, B. Fri . "The distribution alloying elements in alnico 8 and 9 magnets: Site preference of ternary Ti, Fe, Co, and Ni additions in DO{sub 3} Fe{sub 3}Al, Co{sub 3}Al, and Ni{sub 3}Al based intermetallic phases". United States. https://doi.org/10.1063/1.4901229.
@article{osti_22402592,
title = {The distribution alloying elements in alnico 8 and 9 magnets: Site preference of ternary Ti, Fe, Co, and Ni additions in DO{sub 3} Fe{sub 3}Al, Co{sub 3}Al, and Ni{sub 3}Al based intermetallic phases},
author = {Samolyuk, G. D. and Stocks, G. M. and Újfalussy, B.},
abstractNote = {Recently, interest in alnico magnetic alloys has been rekindled due to their potential to substitute for rare-earth based permanent magnets provided modest improvements in their coercivity can be achieved without loss of saturation magnetization. Recent experimental studies have indicated that atomic and magnetic structure of the two phases (one AlNi-based, the other FeCo-based) that comprise these spinodally decomposed alloy is not as simple as previously thought. A key issue that arises is the distribution of Fe, Co, and Ti within the AlNi-based matrix phase. In this paper, we report the results of first-principles calculations of the site preference of ternary alloying additions in DO{sub 3} Fe{sub 3}Al, Co{sub 3}Al, and Ni{sub 3}Al alloys, as models for the aluminide phase. For compound compositions that are Al rich, which correspond to experimental situation, Ti and Fe are found to occupy the α sites, while Co and Ni prefer the γ sites of the DO{sub 3} lattice. An important finding is that the magnetic moments of transition metals in Fe{sub 3}Al and Co{sub 3}Al are ordered ferromagnetically, whereas the Ni{sub 3}Al were found to be nonmagnetic unless the Fe or Co is added as a ternary element.},
doi = {10.1063/1.4901229},
url = {https://www.osti.gov/biblio/22402592}, journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 17,
volume = 116,
place = {United States},
year = {2014},
month = {11}
}