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
By means of both the theory for pressure-induced shifts (PS) of energy spectra and the theory for shiftsof energy spectra due to electron-phonon interaction (EPI), at 300 K, the 'pure electronic' contributions...By means of both the theory for pressure-induced shifts (PS) of energy spectra and the theory for shiftsof energy spectra due to electron-phonon interaction (EPI), at 300 K, the 'pure electronic' contributions and the contri-butions from EPI to R1 line, R2 line, and U band of GGG:Cr3+ as well as their PS have been calculated, respectively.The total calculated results are in good agreement with all the experimental data. Their physical origins have beenexplained. It is found that the mixing-degree of [t2/2(^3T1)e^4T2) and [t3/2^2E) base-wavefunctions in the wavefunctions of R1 level of GGG:Cr^3+ is considerable under normal pressure, and the mixing-degree rapidly decreases with increasingpressure. The change of the mixing-degree with pressure plays a key role for PS of R1 line or R2 line. At 300 K, boththe temperature-independent contribution to R1 line (or R2 line or U band) from EPI and the temperature-dependentone are important. The remarkable difference between pressure-dependent behaviors of PS of R1 lines of GGG:Cr^3+ andGSGG:Cr^3+ results from the differences of their microscopic properties. The features of emission spectra of GGG:Cr^3+at various pressures have satisfactorily been explained.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, 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By means of both the theory for pressure-induced shifts (PS) of energy spectra and the theory for shiftsof energy spectra due to electron-phonon interaction (EPI), at 300 K, the 'pure electronic' contributions and the contri-butions from EPI to R1 line, R2 line, and U band of GGG:Cr3+ as well as their PS have been calculated, respectively.The total calculated results are in good agreement with all the experimental data. Their physical origins have beenexplained. It is found that the mixing-degree of [t2/2(^3T1)e^4T2) and [t3/2^2E) base-wavefunctions in the wavefunctions of R1 level of GGG:Cr^3+ is considerable under normal pressure, and the mixing-degree rapidly decreases with increasingpressure. The change of the mixing-degree with pressure plays a key role for PS of R1 line or R2 line. At 300 K, boththe temperature-independent contribution to R1 line (or R2 line or U band) from EPI and the temperature-dependentone are important. The remarkable difference between pressure-dependent behaviors of PS of R1 lines of GGG:Cr^3+ andGSGG:Cr^3+ results from the differences of their microscopic properties. The features of emission spectra of GGG:Cr^3+at various pressures have satisfactorily been explained.
