Hf–Co and Zr–Co alloys for rare-earth-free permanent magnets

Authors

Balamurugan Balasubramanian, University of Nebraska-LincolnFollow
Bhaskar Das, University of Nebraska-LincolnFollow
Wenyong Zhang, University of Nebraska-LincolnFollow
Ralph Skomski, University of Nebraska at LincolnFollow
David J. Sellmyer, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

2014

Citation

Journal of Physics: Condensed Matter 26:6, 2014

Abstract

The structural and magnetic properties of nanostructured Co-rich transition-metal alloys, Co_100-xTM_x (TM = Hf, Zr and 10 ≤ x ≤ 18), were investigated. The alloys were prepared under nonequilibrium conditions using cluster-deposition and/or melt-spinning methods. The high-anisotropy HfCo₇ and Zr₂Co₁₁ structures were formed for a rather broad composition region as compared to the equilibrium bulk phase diagrams, and exhibit high Curie temperatures of above 750 K. The composition, crystal structure, particle size, and easy-axis distribution were precisely controlled to achieve a substantial coercivity and magnetization in the nanostructured alloys. This translates into high energy products in the range of about 4.3–12.6 MGOe, which are comparable to those of alnico.