| Abstract
| - We present the synthesis, characterization by DT-TGA and IR, single crystal X-ray nuclear structure at 300 K,nuclear and magnetic structure from neutron powder diffraction on a deuterated sample at 1.4 K, and magneticproperties as a function of temperature and magnetic field of Ni3(OH)2(SO4)2(H2O)2. The structure is formed ofchains, parallel to the c-axis, of edge-sharing Ni(1)O6 octahedra, connected by the corners of Ni(2)O6 octahedrato form corrugated sheets along the bc-plane. The sheets are connected to one another by the sulfate groups toform the 3D network. The magnetic properties measured by ac and dc magnetization, isothermal magnetization at2 K, and heat capacity are characterized by a transition from a paramagnet (C = 3.954 emu K/mol and θ = −31K) to a canted antiferromagnet at TN = 29 K with an estimated canting angle of 0.2−0.3°. Deduced from powderneutron diffraction data, the magnetic structure is modeled by alternate pairs of Ni(1) within a chain having theirmoments pointing along [010] and [01̄0], respectively. The moments of Ni(2) atoms are oppositely oriented withrespect to their adjacent pairs. The resulting structure is that of a compensated arrangement of moments withinone layer, comprising one ferromagnetic and three antiferromagnetic superexchange pathways between the nickelatoms.
- The hydrothermally synthesized Ni3(OH)2(SO4)2(H2O)2 consists of ferromagnetically coupled Ni dimers (green) forming chains. The parallel zigzag chains are bridged by NiO6 (blue) into corrugated sheets which are further bridged by SO4 units. The dimers are antiferromagnetically coupled to one another and to the bridging NiO6. The resulting magnetic structure is a canted antiferromagnet below 29 K. The moments are aligned along b which is perpendicular to the chain axis.
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