First-principle study on the surface and interface properties of the half-metallic ferromagnet of rocksalt structural BaC

Recent study showed that rocksalt BaC exhibits half-metallic ferromagnetism (Dong and Zhao, 2011). Here we use the first-principles calculations to investigate the electronic and magnetic properties of the BaC (0 0 1) and (1 1 1) surfaces and the interfaces with the SnSe (1 1 1) substrate. The obtained results reveal that the half-metallicity verified in bulk BaC is preserved at the (0 0 1) and (1 1 1) surfaces. Unfortunately, interfacial configuration shows that the half-metallicity of bulk rocksalt BaC is destroyed for all possible configurations of C–Se, C–Sn, Ba–Se, and Ba–Sn. Moreover, by computing the interface adhesion energies, we evaluate the interfacial adhesive strength for the four possible interfacial structures. We also discuss the changes of the atomic magnetic moments at the (0 0 1) and (1 1 1) surfaces and the interfaces layers with respect to the corresponding bulk values.