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Synthesis, Nuclear, and Magnetic Structures and Magnetic Properties of [Mn 3 (OH) 2 (SO 4 ) 2 (H 2 O) 2 ]
Author(s) -
Ben Salah Mohsen,
Vilminot Serge,
André Gilles,
RichardPlouet Mireille,
BouréeVigneron Françoise,
Mhiri Tahar,
Kurmoo Mohamedally
Publication year - 2004
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200305645
Subject(s) - magnetization , isostructural , crystallography , magnetic moment , crystal structure , atmospheric temperature range , magnetic structure , neutron diffraction , materials science , rietveld refinement , chemistry , nuclear magnetic resonance , condensed matter physics , magnetic field , physics , quantum mechanics , meteorology
[Mn 3 (OH) 2 (SO 4 ) 2 (H 2 O) 2 ] and its deuterated anlaogue were synthesized by a hydrothermal technique and characterized by differential thermal analysis, thermogravimetric analysis, and IR spectroscopy. Its nuclear structure, determined by single‐crystal X‐ray analysis and Rietveld analysis of neutron powder‐diffraction data, consists of a 3D network of chains of edge‐sharing Mn(1)O 6 , running along the c axis, connected by the apices of Mn(2)O 6 and SO 4 units. It is isostructural to the nickel analogue. Determination of the magnetic structure and measurements of magnetization and heat capacity indicate the coexistence of both magnetic long‐range ordering (LRO) and short‐range ordering (SRO) below a Néel temperature of 26 K, while the SRO is retained at higher temperatures. The moments of the two independent Mn atoms lie in the bc plane, and that of Mn(1) rotates continuously by 54° towards the c axis on decreasing the temperature from 25 to 1.4 K. While the SRO may be associated with frustration of the moments within a Mn 3 trimer, the LRO is achieved by antiparallel alignment of the four symmetry‐related trimers within the magnetic unit cell. A spin‐flop field, measured by dc and ac magnetization on a SQUID, is observed at 15 kOe.