Several magnetic semiconductors based on the quaternary Heusler compounds

The successful injection of spin-polarized current into a semiconductor has been expected for a long time in spintronics. The most promising way to achieve it is the use of spin filter materials(SFMs),which are magnetic semiconductors. The diluted magnetic semiconductors (DMSs) such as Ga1-xMnxAs can keep both semiconducting and magnetic behavior. However, this strategy is limited by the low Curie temperatures T_c, which is lower than the room temperature. It is reported that Heusler compounds usually have high Tc . If we can find magnetic semiconductors in Heusler compounds, we may get the high Tc SFMs . The quaternary Heusler compounds have the most complexest ingredient in the Heusler compounds, which means that they may have more possibilities . Employing ab-initio electronic structure calculations within density functional theory, we show that the quaternary Heusler compounds FeNbVAl, FeNbVGa are magnetic semiconductors . We find a rule of searching for magnetic semiconductors by contrasting the band structure of V2FeAl, FeNbVAl, Nb2FeAl, and FeVNbAl . FeNbVGa can also meet this rule . Under this rule we find FeTiCrAl is also magnetic semiconductor . Though we have not found more evidence by now, we hope our finding help researchers find more magnetic semiconductors .