Excited-states play a crucial role in the optical absorption and luminescence of solids and hence their accurate information is highly desired. Herein, we attempt to seize the excited-states information of Mn^(4+)ions...Excited-states play a crucial role in the optical absorption and luminescence of solids and hence their accurate information is highly desired. Herein, we attempt to seize the excited-states information of Mn^(4+)ions in K_(2)SiF_(6) microcrystals via measuring and calculating their variable-temperature photoluminescence excitation(PLE) spectra. At cryogenic temperatures, an unpredicted splitting of the high-excited-state is observed. Moreover, the two-split high-excited-state levels are further revealed to primarily couple with the two hyperfine split modes of quasi-localized ν2 vibration in the distorted Mn-F_(6) octahedral configuration,whereas the coupling strengths are found to be substantially different from each other. The slightly split vibrational mode is firmly supported by the low-temperature Raman spectra. Jahn-Teller lattice distortion is believed to be responsible for the observed splitting of the electronic high-excited-state and the quasi-localized vibrational mode.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 12074324, and 11374247)the Science, Technology, and Innovation Commission of Shenzhen Municipality (Grant Nos. JCJY20180508163404043, and JCYJ20170818141709893)。
文摘Excited-states play a crucial role in the optical absorption and luminescence of solids and hence their accurate information is highly desired. Herein, we attempt to seize the excited-states information of Mn^(4+)ions in K_(2)SiF_(6) microcrystals via measuring and calculating their variable-temperature photoluminescence excitation(PLE) spectra. At cryogenic temperatures, an unpredicted splitting of the high-excited-state is observed. Moreover, the two-split high-excited-state levels are further revealed to primarily couple with the two hyperfine split modes of quasi-localized ν2 vibration in the distorted Mn-F_(6) octahedral configuration,whereas the coupling strengths are found to be substantially different from each other. The slightly split vibrational mode is firmly supported by the low-temperature Raman spectra. Jahn-Teller lattice distortion is believed to be responsible for the observed splitting of the electronic high-excited-state and the quasi-localized vibrational mode.
