Publications

Phase stability and magnetic and electronic properties of a spark plasma sintered CoFe – P soft magnetic alloy

Belcher, Calvin B.; Zheng, baolong Z.; Dickens, Sara D.; Domrzalski, Jessica N.; Langlois, Eric D.; Lehman, Benjamin L.; Pearce, Charles J.; Delany, Robert E.; MacDonald, Benjamin M.; Apelian, Diran A.; Lavernia, Enrique L.; Monson, Todd M.

More efficient power conversion devices are able to transmit greater electrical power across larger distances to satisfy growing global electrical needs. A critical requirement to achieve more efficient power conversion are the soft magnetic materials used as core materials in transformers, inductors, and motors. To that effect it is well known that the use of non-equilibrium microstructures, which are, for example, nanocrystalline or consist of single phase solid solutions, can yield high saturation magnetic polarization and high electrical resistivity necessary for more efficient soft magnetic materials. In this work, we synthesized CoFe – P soft magnetic alloys containing nanocrystalline, single phase solid solution microstructures and studied the effect of a secondary intermetallic phase on the saturation magnetic polarization and electrical resistivity of the consolidated alloy. Single phase solid solution CoFe – P alloys were prepared through mechanically alloying metal powders and phase decomposition was observed after subsequent consolidation via spark plasma sintering (SPS) at various temperatures. The secondary intermetallic phase was identified as the orthorhombic (Co_xFe_1-x)₂P phase and the magnetic properties of the (Co_xFe_1-x)₂P intermetallic phase were found to be detrimental to the soft magnetic properties of the targeted CoFe – P alloy.