Band Structure of the Quaternary Heusler Alloys ScMnFeSn and ScFeCoAl

In our quest for materials with specific applications, a theoretical study plays an important role in predicting the properties of compounds. Heusler alloys or compounds are the most studied in this context. More recently, a lot of quaternary Heusler compounds are investigated for potential applications in fields like Spintronics. We report here our preliminary study of the alloys ScMnFeSn and ScFeCoAl, using the ab-initio linear muffin-tin orbital method within the atomic sphere approximation (LMTO-ASA). The alloy ScMnFeSn shows perfect half-metallicity, namely, one of the spins shows a metallic behaviour and the other spin shows semi-conducting behaviour. Such materials find application in devices such as the spin-transfer torque random access memory (STI-MRAM). In addition, the alloy ScMnFeSn is found to have an integral magnetic moment of 4 mu B, as predicted by the Slater-Pauling rule. The alloy ScFeCoAl does not show half-metallicity.