The electronic structure of the RMn2Ge2 (R = Ca, Y, La, Ba) antiferromagnets

The electronic structure of the tetragonal RMn2Ge2 (R = Ca, Y, La, Ba) anti ferromagnets is presented using the self-consistent Korringa-Kohn-Rostoker method. According to the neutron refinements, two types of collinear antife rromagnetic structure are taken into account: AF(1) for YMn2Ge2 and AF(2) f or the other compounds. The calculated magnetic moments on Mn: 2.17 mu(B) ( YMn2Ge2), 2.84 mu(B) (CaMn2Ge2), 2.95 mu(B) (LaMn2Ge2), and 3.47 mu(B) (BaM n2Ge2) remain in good agreement with the neutron data (in mu(B)) 2.20, 2.67 , 3.05, and 3.66, respectively. As seen on antiferromagnetic density of sta tes, all systems are metallic, however BaMn2Ge2 is found near semimetallic limit. The total energy Korringa-Kohn-Rostoker computations on CaMn2Ge2, pe rformed in both antiferromagnetic phases, result in preferring of the AF(2) structure.