HAL Id: jpa-00215850
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Submitted on 1 Jan 1974
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MAGNETIC INTERACTIONS IN GOLD (II)-BIS (MALEONITRILEDITHIOLATE) OBSERVED BY
197Au MÖSSBAUER SPECTROSCOPY
M. Viegers, J. Trooster
To cite this version:
M. Viegers, J. Trooster. MAGNETIC INTERACTIONS IN GOLD (II)-BIS (MALEONI- TRILEDITHIOLATE) OBSERVED BY 197Au MÖSSBAUER SPECTROSCOPY. Journal de Physique Colloques, 1974, 35 (C6), pp.C6-452-C6-452. �10.1051/jphyscol:1974693�. �jpa-00215850�
MOSSBAUER SPECTRA IN THE PRESENCE OF A FLUCTUATING ELECTRIC l?IEI,D GRADIENT
A. G E R A R D and F. G R A N D J E A N (*) DCpartement de Physique Atomique e t MolCculaire
Institut de Physique, UniversitC de Li&ge, B-4000 Sart-Tilman, Belgique
Rbsumk. - Nous avons developpe, sur la base du travail de Tjon et Blume [I, 21, un mod61e de calcul des spectres Mossbauer en presence d'un gradient de champ electrique fluctuant.
Nous montrons que I'on peut obtenir des spectres avec un doublet ou deux doublets suivant la rapidite des fluctuations.
Le modele s'applique bien aux cas de FeSb2, FeSi et FesSe* ou des electrons se d6localisent pro- gressivement quand la temperature augmente.
Abstract. - On the basis of the work of Tjon and Blume [I, 21, a model for calculating Moss- bauer spectra in the presence of a fluctuating electric field gradient is developed.
It is shown that spectra with one doublet or with two doublets may be obtained depending on the rate of fluctuation.
The model is successfully applied to the cases of FeSbz, FeSi and Fe3Se4, where electrons are progressively delocalized when the temperature is increased.
[I] TJON, J. A. and BLUME, M., Phys. Rev. 165 (1968) 456.
[2] BLUME, M. and TJON, J. A., Phys. Rev. 165 (1968) 446.
(*) Chargk de Recherches du F. N. R. S.
MAGNETIC INTERACTIONS
IN GOLD (11)-BIS (MALEONITRILEDITHIOLATE) OBSERVED BY lg7Au MOSSBAUER SPECTROSCOPY
M. P. A. VIEGERS and J. M. TROOSTER Department of Physical Chemistry
University of Nijmegen, Toernooiveld, Nijmegen, The Netherlands
RBsumB. - On presente des mesures Mossbauer sur le complexe paramagnetique d'Au(I1) : [(n-C4H9)4N]2 [Au(II) (mnt)*] (mnt = maleonitriledithiolate). Le spectre peut &tre interpret6 par une lente relaxation de spin. Le signe du couplage magnbtique hyperfin est nkgatif. Le deplacement isomerique est plus petit que celui de Au(II1) (rnnt);. La discussion des valeurs de I'eclatement quadrupolaire et du deplacement isomerique fait intervenir la covalence des liaisons.
Abstract. - Mossbauer measurements are reported on the paramagnetic Au(I1) complex : [(n-C4H&N]z [Au(II) (mnt)~] (mnt = maleonitriledithiolate). The spectrum can be understood in terms of slow spin relaxation. The sign of the magnetic h y p e r h e coupling is negative. The isomer shift is smaller than that of Au(II1) (mnt);. Both quadrupole splitting and isomer shift are discussed in terms of covalent bonding.
Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1974693
