ISSN:
1432-2021
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
Notes:
Abstract Two natural clinopyroxene single crystals were investigated, an aegirine-augite (AEG) and a magnesian hedenbergite (HED). Both samples were carefully characterized by electron microprobe, X-ray diffraction, and Mössbauer spectroscopy. Magnetic susceptibility measurements of powdered samples reveal low temperature antiferromagnetic coupling and Curie-Weiss behaviour with T N =7.5(5) K, Θ P =−19(1) K for AEG, and T N =31(1) K, Θ P =+21(1) K for HED, respectively. Low temperature Mössbauer spectra exhibit relaxation phenomena. Magnetic susceptibility measurements of the single crystals show the direction of the magnetic moments to be lying within the a/c plane for both samples: 50(±2)° from a and 57(±2)° from c in AEG, and 45(±2)° from a and 60(±2)° from c in HED, respectively. The antiferromagnetic interchain interaction competes with the ferromagnetic intrachain interaction in both pyroxenes. In the magnesian hedenbergite a field induced magnetic transition is found. Its dependence on temperature, magnetic field and crystallographic direction is investigated and described.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002690050041
