کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1411856 1501900 2007 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Jahn–Teller coupling in spinel-type crystals doped with transition metal ions
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Jahn–Teller coupling in spinel-type crystals doped with transition metal ions
چکیده انگلیسی

In this article, we report the theoretical evaluation of the vibronic constants for the spinel-type crystals ZnAl2S4, ZnAl2Se4, CdAl2Se4, and CdIn2S4 doped with the transition metal ions Cr3+, Cr4+, Ti2+, and Ti3+. In these crystals the ions Cr3+, Ti3+ and Cr4+, Ti2+ occupy positions with octahedral and tetrahedral surrounding correspondingly. In the case of a tetrahedral complex the interaction with full symmetric A1, tetragonal E   and two trigonal vibrations T2(1) and T2(2) is considered, while for the octahedral cluster along with the A1 and E vibrations only one trigonal vibrational mode is taken into account. The examined semiconductor systems are mainly covalent and application of the crystal field point charge model loses proper exactity. For this reason, we employ the exchange charge model for the crystal field that accounts for the covalence effects and provides relatively simple expressions for the crystal field and vibronic parameters keeping at the same time a reasonable level of accuracy. The vibronic coupling constants are numerically calculated and for each case an appropriate multi-mode Jahn–Teller vibronic problem is found out.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure - Volume 838, Issues 1–3, 16 July 2007, Pages 133–137
نویسندگان
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