Hf-Co and Zr-Co alloys for rare-earth-free permanent magnets.
The structural and magnetic properties of nanostructured Co-rich transition-metal alloys, Co(100-x)TMx (TM = Hf, Zr and 10 ≤ x ≤ 18), were investigated. The alloys were prepared under non-equilibrium 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.
B
B
Balamurugan
B
B
Das
W Y
WY
Zhang
R
R
Skomski
D J
DJ
Sellmyer
D000497:Alloys / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry; D006195:Hafnium / Q000737:chemistry; D059346:Magnets / Q000737:chemistry*; D019216:Metals, Heavy / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D036103:Nanotechnology; D010316:Particle Size; D015040:Zirconium / Q000737:chemistry
D000497:Alloys; D019216:Metals, Heavy; D003035:Cobalt; D015040:Zirconium; D006195:Hafnium