language: de

ESR-Untersuchungen an antiferromagnetischem CrN zum Einfluß der Temperatur auf die Austausch-Wechselwirkung

K. Dräger
Institut für Physikalische Chemie, Universität Hamburg
und R. Gerling
Institut für Physik, GKSS-Forschungszentrum Geesthacht GmbH.
Z. Naturforsch. 85a, 475—482 (1980);

[eingegangen am 28. Februar 1980]

[ESR-Investigation on Antiferromagnetie CrN Concerning the Influence of Temperature on the Exchange-Interaction]

The ESR-behaviour of antiferromagnetie and almost stoechiometric CrN is thoroughly investigated above its Neel-point. For polycrystalline samples a spectroscopic splitting factor g =1.965 and a differential line width AB = 56,7 mT is measured at room temperature. All resonance lines exhibit Lorentzian character to a high degree. In the temperature range between 300 K and 520 K the ESR-intensity can satisfactorily be described by a model of local ordering. Its binding energy is computed to be about AE — 500 ± 20 cm-1. A more refined analysis snows a systematic change of AE with temperature and a discrepancy between the Neel-point TN and the temperature Ts characterizing a singular behaviour of the line width AB. Apart from these deviations originating in a magnetic ordering of the fourth kind, the cluster-model gives an isotropic exchange between next nearest neighbours of J% = — 33.2 cm-1. This result is confirmed by molecular field computations.

Einleitung