Synthesis, crystal structure, and magnetic properties of CoMoFeAl and related compounds

Abstract

We have carried out joint theoretical and experimental investigations of three Heusler compounds CoMoFeAl, CoMo0.5Fe1.5Al, and Co1.5Mo0.5FeAl. Our first-principle calculations show that all three compounds show either ferro- or ferrimagnetic order with CoMoFeAl and CoMo0.5Fe1.5Al exhibiting high spin polarization of almost 80%. The investigated samples were prepared using arc melting and high vacuum annealing. All the samples show cubic crystal structure with disorder. The parent compound CoMoFeAl shows a small saturation magnetization of 12 emu/g, and a Curie temperature of 440 K. The other two compounds, namely, Co1.5Mo0.5FeAl and CoMo0.5Fe1.5Al, show much higher saturation magnetizations of 62 emu/g and 59 emu/g, and substantially higher Curie temperatures of 950 K and 780 K, respectively.