2013 Volume 54 Issue 12 Pages 2309-2312
First-principles total-energy calculations have been performed for the hypothetical case of x = 1 in Mn2−xXxSb (X = Co and Cu) for several magnetic states, using the full-potential linearized augmented plane wave method based on the generalized gradient approximation. The calculated total energy indicates that the Co (Cu) atom prefers the site Mn(I) to the site Mn(II) (Mn(II) to Mn(I)). This result of Co is consistent with the available neutron diffraction experiment. For CoMnSb where Co occupies the site Mn(I), the change of lattice constants (a and c) and c/a from AF2 to F is in good agreement with experimental trends. Our results indicate that the optimization of the ratio c/a (lattice distortion) is crucial to determine the most stable magnetic state and that the optimization of the atomic positions of the sites Mn(II) and Sb is also crucial.