Isotopic phonon effects in LaB6-LaB6 do not possess cubic symmetry and show a non-random isotope distribution.

Abstract

The isotopic phonon effects in LaB(6) are investigated on the Raman spectra of a series of high-quality single crystals with systematically varied contents of (10)B and (11)B isotopes. A detailed group theoretical analysis enlightens the correlation between distortions of the B(6) octahedra and the splitting or broadening of phonon modes. It is evident that LaB(6) does not have cubic symmetry as assumed so far. A further symmetry reduction of the B(6) octahedra occurs in isotopically mixed crystals. There, the distribution of isotopes is not random as commonly assumed; the probability of associating equal isotopes increases with their mass decreasing.

DOI: 10.1088/0953-8984/24/38/385405

Cite this paper

@article{Werheit2012IsotopicPE, title={Isotopic phonon effects in LaB6-LaB6 do not possess cubic symmetry and show a non-random isotope distribution.}, author={Helmut Werheit and V. Filipov and N Yu Shitsevalova and Marc Armbruester and Ulrich S. Schwarz}, journal={Journal of physics. Condensed matter : an Institute of Physics journal}, year={2012}, volume={24 38}, pages={385405} }