High energy product of MnBi by field annealing and Sn alloying

Authors

Wenyong Zhang, University of Nebraska - Lincoln
Balamurugan Balasubramanian, University of Nebraska-LincolnFollow
Parashu Kharel, University of Nebraska - Lincoln
Rabindra Pahari, University of Nebraska - LincolnFollow
Shah R. Valloppilly, University of Nebraska - LincolnFollow
Xingzhong Li, University of Nebraska-LincolnFollow
Lanping Yue, University of Nebraska - LincolnFollow
Ralph Skomski, University of Nebraska-LincolnFollow
David J. Sellmyer, University of Nebraska - LincolnFollow

ORCID IDs

Wenyong Zhang

Balamurugan Balasubramanian

Parashu Kharel

Rabindra Pahari

Shah R. Valloppilly

Xingzhong Li

Lanping Yue

Ralph Skomski

David J. Sellmyer

Date of this Version

2019

Citation

APL Mater. 7, 121111 (2019)

Comments

© Author(s) 2019

doi: 10.1063/1.5128659

Abstract

Permanent-magnet materials are one cornerstone of today’s technology, abundant in disk drives, motors, medical equipment, wind generators, and cars. A continuing challenge has been to reconcile high permanent-magnet performance with low raw-material costs. This work reports a Mn-Bi-Sn alloy exclusively made from inexpensive elements, exhibiting high values of Curie-temperature, magnetization, anisotropy, coercivity, and energy product. The samples are produced by field annealing of rapidly quenched Sn-containing MnBi alloys, where the improvement of the magnetic properties is caused by the substitutional occupancy of the 2c sites in the hexagonal NiAs structure by Sn. The substitution modifies the electronic structure of the compound and enhances the magnetocrystalline anisotropy, thereby improv- ing the coercivity of the compound. The energy product reaches 114 kJ/m³ (14.3 MGOe) at room temperature and 86 kJ/m³ (10.8 MGOe) at 200^○C; this value is similar to that of the Dy-free Nd₂Fe₁₄B and exceeds that of other rare-earth-free permanent-magnet bulk alloys, as encountered in automotive applications.