Ferromagnetism in the half-heusler XCsBa compounds from first-principles calculations (X = C, Si, and Ge)

Highlights: ► Ab-initio prediction on the magnetic properties of XCsBa half-heusler, X = C, Si and Ge. ► These hypothetical compounds are half-metal ferromagnets in their stable structure. ► The magnetism is due to the polarization p-states of X = C, Si and Ge. ► The use of the mBJ improves the electronic and magnetic results. -- Abstract: We present an overview on the magnetic properties of the half-heusler XCsBa compounds (where X = C, Si and Ge). The spin-polarized calculations by use of the full potential linear-augmented-plane waves method, indicate that these materials are half-metallic ferromagnets with an integer magnetic moment of 1 μB. The most important property is that the ferromagnetism is originated from the polarization of the p-X orbitals with an sp-hybridization. We give also a comparison between the standard generalized gradient approximation (GGA) and the modified Becke–Johnson exchange potential approximation (mBJ–GGA) on the electronic and magnetic properties