Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one （including lattice-vibrational relaxation energy）. By means of improved...Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one （including lattice-vibrational relaxation energy）. By means of improved ligand-field theory, the R-line, t^3 2^2 T1 lines, t^2 2（^3 T1）e^4 T2, and t^2 2（^3T1）e^4T1 bands, ground-state g factor, four strain-induced level- splittings, and R-line thermal shift of MgO：Cr^3＋ have been calculated. The results are in very good agreement with the experimental data. It is found that for MgO：Cr^3＋, the contributions due to electron-phonon interaction （EPI） come from the first-order term. In thermal shift of R-line of MgO：Cr^3＋, the temperature-dependent contribution due to EPI is dominant.展开更多
Traditional ligand-field theory has to be improved by taking into account both 'pure electronic' contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy). By means of ...Traditional ligand-field theory has to be improved by taking into account both 'pure electronic' contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy). By means of improved ligand-field theory, R1, R2, R'3, R'2, and R'1 lines, U band, ground-state zero-field-splitting (GSZFS), and ground-state g factors of ruby and/or GSGG: Cr3+ as well as thermal shifts of GSZFS, R1 line and R2 line of ruby have been calculated.The results are in very good agreement with the experimental data. Moreover, it is found that the value of cubic-field parameter given by traditional ligand-field theory is inappropriately large. For thermal shifts of GSZFS, R1 line and R2 line of ruby, several conclusions have also been obtained.展开更多
Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one （including lattice-vibrational relaxation energy）. By means of improved...Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one （including lattice-vibrational relaxation energy）. By means of improved ligand-field theory, the R line, t^322T1 and t^322T2 lines, t^22（^3T1）e^4T2, t^22（^3T1）e^4T1 and t2e^2（^4A2）4T1 bands, g factors of t^32 ^4A2 and t32E, four strain-induced level-splittings and R-line thermal shift of MgO：V^2＋ have been calculated. The results are in very good agreement with the experimental data. It is found that for MgO：V^2＋, the contributions due to electronphonon interaction （EPI） come from the first-order term; the contributions from the second-order and higher terms are insignificant. In thermal shift of R line of MgO：V^2＋, the temperature-dependent contribution due to EPI is dominant. The results obtained in this work may be used in theoretical calculations of other effects of EPI.展开更多
By extending the usual DV-X_α calculation and applying Bird's ligand-field theory, wepresent a theoretical method for calculating d-d ligand-field spectra of transition-metal com-plexes. Comparison between the ca...By extending the usual DV-X_α calculation and applying Bird's ligand-field theory, wepresent a theoretical method for calculating d-d ligand-field spectra of transition-metal com-plexes. Comparison between the calculated d-d ligand-field spectrum and the experimental (orother theoretical) results of cluster (CrF_6)^(3-) shows that this method is convenient and ef-fective.展开更多
The electron paramagnetic spectra of trigonal Mn^(2+) centers in[Co(H_(2)O)_(6)]SiF6,[Co(H_(2)O)_(6)]SnF6,and[Co(H_(2)O)_(6)]PtCl6 crystals were studied on the basis of the complete energy matrices for a d5 configurat...The electron paramagnetic spectra of trigonal Mn^(2+) centers in[Co(H_(2)O)_(6)]SiF6,[Co(H_(2)O)_(6)]SnF6,and[Co(H_(2)O)_(6)]PtCl6 crystals were studied on the basis of the complete energy matrices for a d5 configuration ion in a trigonal ligand field.When Mn^(2+) is doped in the[Co(H_(2)O)_(6)]SiF6,[Co(H_(2)O)_(6)]SnF6,and[Co(H_(2)O)_(6)]PtCl6 crystals crystals,there is a similar local distortion.The experimental results show that the local lattice structure around a trigonal Mn^(2+) center has an elongation distortion along the crystalline C3 axis.From the EPR calculation,the local lattice structure parameters R=2.278A,θ=52.6406? for[Co(H_(2)O)_(6)]SiF6,R=2.280,θ=52.4936° for[Co(H_(2)O)_(6)]SnF6 and R=2.244A,θ=53.0616? for[Co(H_(2)O)_(6)]PtCl6 were determined.展开更多
The electron paramagnetic resonance（EPR） spectra of trigonal Mn^（2＋） centers in Zn（ClO4）2·6（H2O） and Mg（ClO4）2·6（H2O） crystals were studied on the basis of the complete energy matrices for a d^5...The electron paramagnetic resonance（EPR） spectra of trigonal Mn^（2＋） centers in Zn（ClO4）2·6（H2O） and Mg（ClO4）2·6（H2O） crystals were studied on the basis of the complete energy matrices for a d^5 configuration ion in a trigonal ligand field. It was demonstrated that the local lattice structure around a trigonal Mn^（2＋） center has an compressed distortion along the crystalline c3 axis, and when Mn^（2＋） is doped in the Zn（ClO4）2·6（H2O） and Mg（ClO4）2·6（H2O） crystals, there is a similar local distortion. From the EPR calculation, the local lattice structure parameters R=2.183 2 ？, for Zn（ClO4）2·6（H2O）, R=2.130 2 ？, for Mg（ClO4）2·6（H2O） have been determined.展开更多
文摘Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one （including lattice-vibrational relaxation energy）. By means of improved ligand-field theory, the R-line, t^3 2^2 T1 lines, t^2 2（^3 T1）e^4 T2, and t^2 2（^3T1）e^4T1 bands, ground-state g factor, four strain-induced level- splittings, and R-line thermal shift of MgO：Cr^3＋ have been calculated. The results are in very good agreement with the experimental data. It is found that for MgO：Cr^3＋, the contributions due to electron-phonon interaction （EPI） come from the first-order term. In thermal shift of R-line of MgO：Cr^3＋, the temperature-dependent contribution due to EPI is dominant.
文摘Traditional ligand-field theory has to be improved by taking into account both 'pure electronic' contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy). By means of improved ligand-field theory, R1, R2, R'3, R'2, and R'1 lines, U band, ground-state zero-field-splitting (GSZFS), and ground-state g factors of ruby and/or GSGG: Cr3+ as well as thermal shifts of GSZFS, R1 line and R2 line of ruby have been calculated.The results are in very good agreement with the experimental data. Moreover, it is found that the value of cubic-field parameter given by traditional ligand-field theory is inappropriately large. For thermal shifts of GSZFS, R1 line and R2 line of ruby, several conclusions have also been obtained.
文摘Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one （including lattice-vibrational relaxation energy）. By means of improved ligand-field theory, the R line, t^322T1 and t^322T2 lines, t^22（^3T1）e^4T2, t^22（^3T1）e^4T1 and t2e^2（^4A2）4T1 bands, g factors of t^32 ^4A2 and t32E, four strain-induced level-splittings and R-line thermal shift of MgO：V^2＋ have been calculated. The results are in very good agreement with the experimental data. It is found that for MgO：V^2＋, the contributions due to electronphonon interaction （EPI） come from the first-order term; the contributions from the second-order and higher terms are insignificant. In thermal shift of R line of MgO：V^2＋, the temperature-dependent contribution due to EPI is dominant. The results obtained in this work may be used in theoretical calculations of other effects of EPI.
基金Project supported by the National Natural Science Foundation of China.
文摘By extending the usual DV-X_α calculation and applying Bird's ligand-field theory, wepresent a theoretical method for calculating d-d ligand-field spectra of transition-metal com-plexes. Comparison between the calculated d-d ligand-field spectrum and the experimental (orother theoretical) results of cluster (CrF_6)^(3-) shows that this method is convenient and ef-fective.
基金Funded by the National Natural Science Foundation of China (Nos. 11804285 and 61601384)。
文摘The electron paramagnetic spectra of trigonal Mn^(2+) centers in[Co(H_(2)O)_(6)]SiF6,[Co(H_(2)O)_(6)]SnF6,and[Co(H_(2)O)_(6)]PtCl6 crystals were studied on the basis of the complete energy matrices for a d5 configuration ion in a trigonal ligand field.When Mn^(2+) is doped in the[Co(H_(2)O)_(6)]SiF6,[Co(H_(2)O)_(6)]SnF6,and[Co(H_(2)O)_(6)]PtCl6 crystals crystals,there is a similar local distortion.The experimental results show that the local lattice structure around a trigonal Mn^(2+) center has an elongation distortion along the crystalline C3 axis.From the EPR calculation,the local lattice structure parameters R=2.278A,θ=52.6406? for[Co(H_(2)O)_(6)]SiF6,R=2.280,θ=52.4936° for[Co(H_(2)O)_(6)]SnF6 and R=2.244A,θ=53.0616? for[Co(H_(2)O)_(6)]PtCl6 were determined.
基金Funded in Part by the National Natural Science Foundation of China(No.61601384)
文摘The electron paramagnetic resonance（EPR） spectra of trigonal Mn^（2＋） centers in Zn（ClO4）2·6（H2O） and Mg（ClO4）2·6（H2O） crystals were studied on the basis of the complete energy matrices for a d^5 configuration ion in a trigonal ligand field. It was demonstrated that the local lattice structure around a trigonal Mn^（2＋） center has an compressed distortion along the crystalline c3 axis, and when Mn^（2＋） is doped in the Zn（ClO4）2·6（H2O） and Mg（ClO4）2·6（H2O） crystals, there is a similar local distortion. From the EPR calculation, the local lattice structure parameters R=2.183 2 ？, for Zn（ClO4）2·6（H2O）, R=2.130 2 ？, for Mg（ClO4）2·6（H2O） have been determined.
