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Hydrothermal Synthesis, Structure and Magnetic Properties of a One‐Dimensional Iron Arsenate, 1 ∞ [NH 3 (CH 2 ) 2 NH(CH 2 ) 2 NH 3 ][Fe 2 F 4 (HAsO 4 ) 2 ]
Author(s) -
Chakrabarti Sandip,
Pati Swapan K.,
Green Mark A.,
Natarajan Srinivasan
Publication year - 2004
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200400127
Subject(s) - chemistry , antiferromagnetism , octahedron , arsenate , crystallography , excited state , magnetic susceptibility , hydrothermal circulation , hydrothermal synthesis , ground state , singlet state , spin (aerodynamics) , spins , tetrahedron , ion , crystal structure , condensed matter physics , arsenic , atomic physics , physics , seismology , geology , thermodynamics , organic chemistry
A novel one‐dimensional iron arsenate, 1 ∞ [NH 3 (CH 2 ) 2 NH(CH 2 ) 2 NH 3 ][Fe 2 F 4 (HAsO 4 ) 2 ], built up exclusively from SBU‐4 units (two octahedral units sharing an edge and connected through two tetrahedra) with Fe 3+ ions in the high‐spin state has been synthesized by hydrothermal methods. Structure elucidation reveals that the compound is a two‐leg ladder with very weak antiferromagnetic exchanges along the chains. The magnetic susceptibility data show activated behaviour at T = 14 K, suggesting a finite spin gap between the nonmagnetic ground state and the excited triplet state. We have estimated the exchange parameters theoretically based on the S = 5/2 Majumdar−Ghosh model with frustrations and dimerisations. Although the magnetic gap is quite small, this is the first example, to the best of our knowledge, where the rungs with two S = 5/2 spins form strong singlet dimers. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)