Spin configuration of Mn(HCOO)(2) center dot 2(NH2)(2)CO

The magnetic spin arrangement of Mn2+ in the crystal of manganese formate d i-urea, Mn(HCOO)(2) . (2)(NH2)(2)CO, is investigated within the Weiss molec ular field approximation at T = 0. This compound has the P4(1)2(1)2 tetrago nal crystal structure and is a rather complicated antiferromagnet with eigh t sublattices. It is shown that this spin configuration is possible by taki ng into account the anisotropy energies due to the magnetic dipole field an d the anisotropic exchange field, both caused by the small displacement of Mn2+ from the perfect lattice sites, in addition to the superexchange inter actions between the magnetic spins. (C) 2000 Elsevier Science B.V. All righ ts reserved.