Abstracts 2001

Abstract of Publication No. 390

Oliver S. Wenger, Rafael Valiente and Hans U. Güdel
Influence of hydrostatic pressure on the Jahn-Teller effect in the 4T2g excited state of CrCl63- doped Cs2NaScCl6
J. Chem. Phys. 115, 3819-3826 (2001)      Full Text (PDF)      DOI-Link     

Abstract: The 4T2g 4A2g luminescence of a 4.1% Cr3+ doped Cs2NaScCl6 crystal is studied as a function of hydrostatic pressure at room temperature and 15 K. The vibrational fine structure observed in the low-temperature variable pressure emission spectra is analyzed with a two configurational coordinate approach, involving the totally symmetric a1g and the eg Jahn-Teller normal coordinate. Increasing hydrostatic pressure is found to reduce the tetragonal distortion of the CrCl63- unit in the electronic 4T2g state resulting from the Jahn-Teller effect. Additionally, pressure impedes expansion along the a1g coordinate of the CrCl63- complex upon 4A2g 4T2g photo-excitation, and thus has a greater influence on the 4T2g excited state than on the 4A2g ground state. The absolute Cr3+ - Cl average distance reduction upon increasing pressure is estimated using a simple point charge model.

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