Jahn-Teller interaction at Cr2+(d4) centres in tetrahedrally coordinated II–VI lattices studied by optical spectroscopy

摘要: Optical spectra of thed4 configuration have been studied with II–VI compounds. Failure static crystal-field description led various authors to introduce or dynamic Jahn-Teller models for the Cr2+ ground and excited states. With ZnS, main optical transition5E(D)↔5T2(D) now appears as a doublet at 5218 5212 cm−1 coinciding emission absorption spectra. This no-phonon structure indicates splitting gound-and excited-state multiplets under combined spin-orbit interactions. In cubic host ZnSe in hexagonal compounds CdS CdSe, properties exhibit same general behaviour but decreasing shaping structural details. addition NIR measurements, middle-infrared recorded by Fourier spectroscopy transmission mode. For first time broad band could be detected ZnS interpreted the\(^5 \hat E\left( {T_2 } \right) \leftarrow ^5 B\left( \right)\) between sheets respective adiabatic potential surfaces inD2d symmetry. Its maximum near 1300 indicates\(\bar v_{JT} \approx 430cm^{ - 1} \) following common interpretation this transition.