Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

Iowa State University

Density functional theory

Materials Science and Engineering

2014

Articles 1 - 1 of 1

Full-Text Articles in Physics

Anomalous Magneto-Structural Behavior Of Mnbi Explained: A Path Towards An Improved Permanent Magnet, Nikolai A. Zarkevich, Linlin Wang, Duane D. Johnson Jan 2014

Anomalous Magneto-Structural Behavior Of Mnbi Explained: A Path Towards An Improved Permanent Magnet, Nikolai A. Zarkevich, Linlin Wang, Duane D. Johnson

Ames Laboratory Publications

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 susceptibilitymaximum near 90 K, and, importantly for high-temperature magnetic applications, an increasingcoercivity (unique to MnBi) above 180  K. We calculate the total energy and magneto-anisotropyenergy (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.