Investigation Of Magnetization Reversal In Sm-Fe-Cu(Zr)-Ga-C Nanocomposite Magnets

A comparative study has been performed concerning the microstructure and the magnetization reversal behavior of nearly single-phase Sm2Fe14.5Cu0.5Ga2C2 and two-phase exchange-coupled Sm2Fe14.5Cu0.5Ga2C2/alpha-Fe and Sm2Fe14.25Zr0.25Cu0.5Ga2C2/alpha-Fe synthesized by melt spinning and annealing. A few percent of Zr substitution proved to be effective in refining the microstructure and enhancing exchange-spring behavior after melt spinning and annealing. All samples show remanence enhancement, the value of M-r/M-s being the largest for the sample containing Zr. Measurements of the reversible susceptibility show a large reversible magnetization in the two-phase materials. For the Zr-containing sample, a more detailed analysis of the temperature dependence of the exchange-spring behavior was made. (C) 2000 American Institute of Physics. [S0021-8979(00)10103-3].