No abstract

No abstract

Infrared absorption and luminescence measurements of substitutional Cr2+(d4) in the II-VI compounds ZnS, ZnSe, ZnTe and CdTe are reported. The experimental results are interpreted in the framework of crystal field theory with spin-orbit coupling and a substantial Jahn-Teller interaction in the 5T2 ground state and a much smaller, but significant, Jahn-Teller interaction in the excited 5E state. With a semiclassical model and a Monte Carlo computing technique convoluted shapes of absorption and luminescence spectra are obtained. The Jahn-Teller energy for the 5T2 ground state is found to be approximately 350 cm-1. For the first time a Jahn-Teller energy for the excited 5E state is reported, and has a value of approximately 50 cm-1. The inclusion of ligand field effects in the spin-orbit coupling constant was found to be important.

No abstract

The absorption spectra of Ti (dz), V (ds), Cr (d4), Fe (ds), Co (d'), Ni (d*), and Cu (dg) in CdSe crystals are presented. The main features of the spectra are successfully interpret,ed using crystal-field theory for the states of 3dn configuration in a potential of predominantly Td symmetry. It is found that the oscillator strengths of the observed absorption bands are in the range 10-2 to 10-5 due to transitions within the 3dn shell. The crystal-field parameters, A, and the Racah parameters, B and C, are determined where possible, and discussed.Die Absorptionsspektren von Ti (d2), V (d3), Cr (d4), Fe (dE), Co (d7), Ni (d*) und Cu (ds) in CdSe-Kristallen werden mitgeteilt. Die Hauptcharakteristiken der Spektren lassen sich erfolgreich mittels Kristallfeldtheorie fiir Zustinde der 3d"-Konfiguration, auf die ein Potential mit uberwiegender Ta-Symmetrie wirkt, interpretieren. Es wird gefunden, daB die Oszillatorstirken der beobachteten Absorptionsbanden fur Ubergenge innerhalb der 3d7-Schale im Bereich von 10-2 bis 10-6 liegen. Die Kristallfeldparameter A und die RacahParameter B und C werden, soweit moglich, bestimmt und diskutiert.