Published 1976 | Version v1
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Vibronic effects deduced from the hyperfine interactions induced by an outer magnetic field: Fe2+ ion at an octaedric site in KMgF3 and CaO

Creators

Description

The dynamic Jahn-Teller effect was investigated in MgO:Fe2+, KMgF3:Fe2+ and CaO:Fe2+ octahedral complexes. Transmission measurements as a function of the temperature and concentration were carried out in the far infrared. For KMgF3:Fe2+, the complexity of the spectrum between 10 and 120 cm-1 made necessary a field effect study in view of separating the absorption peaks corresponding to the electron transitions from those corresponding to phonon resonance absorption. The field effect Moessbauer spectroscopy gave the variations in the quadrupole interaction and hyperfine field induced by the outer field. Three different aspects appear for the Jahn-Teller effect: for MgO:Fe2+ a weak coupling approximately equal to the E(g) and T(2g) modes of the complex, for KMgF3:Fe2+ an important coupling dominant with the T(2g) vibration modes of the complex, for CaO:Fe2+ a strong coupling dominant with the E(g) vibration modes of the complex

Abstract (French)

On a etudie l'effet Jahn-Teller dynamique dans les complexes octaedriques MgO:Fe2+, KMgF3:Fe2+ et CaO:Fe2+. Des mesures de transmission en fonction de la temperature et de la concentration ont ete effectuees dans l'infrarouge lointain. En ce qui concerne KMgF3:Fe2+ la complexite du spectre entre 10 et 120 cm-1 a rendu indispensable l'etude sous champ pour separer les pics d'absorption correspondant aux transitions electroniques de ceux correspondant a l'absorption resonnante de phonons. La spectrometrie Moessbauer sous champ a fourni la variation de l'interaction quadripolaire et du champ magnetique hyperfin induits par le champ exterieur. Trois situations differentes pour le couplage Jahn-Teller: pour MgO:Fe2+, un couplage faible et sensiblement egal avec les modes E(g) et T(2g) du complexe; pour KMgF3:Fe2+, couplage important et dominant avec les modes de vibration T(2g) du complexe; pour CaO:Fe2+ couplage fort et dominant avec les modes de vibration E(g) du complexe

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Additional details

Additional titles

Original title (French)
Effets vibroniques deduits des interactions hyperfines induites par un champ magnetique exterieur: cas de l'ion Fe

Publishing Information

Imprint Title
Grenoble Fundamental Research Department
Imprint Pagination
p. 84-93.
Report number
CEA-N--1897

INIS

Country of Publication
France
Country of Input or Organization
France
INIS RN
8291377
Subject category
S75: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY;
Resource subtype / Literary indicator
Progress Report
Descriptors DEI
COUPLING; ELECTRON SPIN RESONANCE; IMPURITIES; IRON IONS; IRON 57; MAGNESIUM OXIDES; MOESSBAUER EFFECT; VALENCE
Descriptors DEC
ALKALINE EARTH METAL COMPOUNDS; ATOMIC IONS; CHALCOGENIDES; CHARGED PARTICLES; EVEN-ODD NUCLEI; INTERMEDIATE MASS NUCLEI; IONS; IRON ISOTOPES; ISOTOPES; MAGNESIUM COMPOUNDS; MAGNETIC RESONANCE; NUCLEI; OXIDES; OXYGEN COMPOUNDS; RESONANCE; STABLE ISOTOPES

Optional Information

Notes
Imprint:Departement de Recherche Fondamentale de Grenoble.;Bulletin semestriel no. 9, 1976, 1. semestre.