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:1211332

Zarkevich, NA; Wang, LL; Johnson, DD

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. (C) 2014 Author(s).

• Sponsoring Organization: USDOE Advanced Research Projects Agency - Energy (ARPA-E)
• DOE Contract Number: 0472-1526
• OSTI ID: 1211332
• Journal Information: APL Materials, Vol. 2, Issue 3; ISSN 2166-532X
• Country of Publication: United States
• Language: English