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Cerium-iron-based magnetic compounds

United States Patent

9,548,150
January 17, 2017
View the Complete Patent at the US Patent & Trademark Office
New magnetic materials containing cerium, iron, and small additions of a third element are disclosed. These materials comprise compounds Ce(Fe.sub.12-xM.sub.x) where x=1-4, having the ThMn.sub.12 tetragonal crystal structure (space group I4/mmm, #139). Compounds with M=B, Al, Si, P, S, Sc, Co, Ni, Zn, Ga, Ge, Zr, Nb, Hf, Ta, and W are identified theoretically, and one class of compounds based on M=Si has been synthesized. The Si cognates are characterized by large magnetic moments (4.pi.M.sub.s greater than 1.27 Tesla) and high Curie temperatures (264.ltoreq.T.sub.c.ltoreq.305.degree. C.). The Ce(Fe.sub.12-xM.sub.x) compound may contain one or more of Ti, V, Cr, and Mo in combination with an M element. Further enhancement in T.sub.c is obtained by nitriding the Ce compounds through heat treatment in N.sub.2 gas while retaining the ThMn.sub.12 tetragonal crystal structure; for example CeFe.sub.10Si.sub.2N.sub.1.29 has T.sub.c=426.degree. C.
Zhou; Chen (Warren, MI), Pinkerton; Frederick E. (Shelby Township, MI), Herbst; Jan F. (Grosse Pointe Woods, MI)
GM Global Technology Operations LLC (Detroit, MI)
13/ 786,807
March 6, 2013
This invention was made with U.S. Government support under Agreement No. DE-AR0000195 awarded by the Department of Energy. The U.S. Government may have certain rights in this invention.