Anomalous magneto-structural behavior of MnBi explained: A path towards an improved permanent magnet

Journal Article · Sat Mar 01 00:00:00 EST 2014 · APL Materials

DOI:https://doi.org/10.1063/1.4867223· OSTI ID:22269551

Wang, L. -L. ^[1]; Johnson, D. D. ^[1]

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1. The Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011 (United States)

Low-temperature MnBi (hexagonal NiAs phase) exhibits anomalies in the lattice constants (a, c) and bulk elastic modulus (B) below 100 K, spin reorientation and magnetic susceptibility maximum near 90 K, and, importantly for high-temperature magnetic applications, an increasing coercivity (unique to MnBi) above 180  K. We calculate the total energy and magneto-anisotropy energy (MAE) versus (a, c) using DFT+U methods. We reproduce and explain all the above anomalies. We predict that coercivity and MAE increase due to increasing a, suggesting means to improve MnBi permanent magnets.

• OSTI ID: 22269551
• Journal Information: APL Materials, Vol. 2, Issue 3; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 2166-532X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANISOTROPY
COERCIVE FORCE
LATTICE PARAMETERS
MAGNETIC SUSCEPTIBILITY
PERMANENT MAGNETS
SPIN