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Antisymmetric and Anisotropic Exchange as Studied by EPR in a Molecular Composite [NH 3 ‐(CH 2 ) 2 ‐NH 3 ]CuCl 4
Author(s) -
Bissey J.Cl.,
Filloleau N.,
Beziade P.,
Chanh NguyenBa,
Zouari R.,
Daoud A.
Publication year - 1997
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/1521-3951(199706)201:2<505::aid-pssb505>3.0.co;2-2
Subject(s) - electron paramagnetic resonance , monoclinic crystal system , anisotropy , ion , crystallography , copper , chemistry , laser linewidth , crystal structure , nuclear magnetic resonance , physics , optics , laser , organic chemistry
The monoclinic crystal structure of [NH 3 ‐(CH 2 ) 2 ‐NH 3 ]CuCl 4 consists of two‐dimensional ( b , c ) layers of square planar (CuCl 4 ) 2— entities, separated from each other by [NH 3 ‐(CH 2 ) 2 ‐NH 3 ] 2+ alkylene chain sheets. Electron Paramagnetic Resonance (EPR) data have been obtained in single crystals of 2C2CuCl4 when rotated around a *, b and c ‐axes, at X‐band. Only one EPR exchange‐collapsed line was observed for the two magnetically inequivalent copper ions in the lattice. The angular variation of its position and peak‐to‐peak linewidth were measured in three perpendicular planes. A careful analysis of experimental data permits to obtain the principal values of the g ‐factor g ⊥ = 2.053, g | = 2.274. The contributions to the linewidths were analyzed in terms of the antisymmetric exchange ( d ) and the anisotropic exchange ( D ) and yielded | d x / d y | = 0.92 and |( d 2 x + 2.2 D 2 ) 1/2 / d y | = 0.65. Lineshape studies show that the exchange between the two inequivalent copper ions is anisotropic.