Ternary manganese compounds AMnX (A = Mg, Ca, Sr or Ba; X = Si, Ge or Sn): Characterization of the magnetic properties by neutron diffraction experiments

Neutron diffraction experiments led to the determination of the antiferromagnetic spin structures of MgMnGe, CaMnSi, CaMnGe, CaMnSn, SrMnGe, SrMnSn, and BaMnGe. For the compounds MgMnGe, CaMnSi, CaMnGe, and CaMnSn an arrangement was found that can be described in the crystallographic cell; in the case of SrMnGe, SrMnSn, and BaMnGe the c-axes have to be doubled. The Shubnikov-groups are P4'/n'm'm and P4'/n'cc', respectively. The magnetic moments of the maganese atoms are significantly below those values to be expected for Mn2+ ions.