As a key factor leading to the pressure-dependent R1-line-shift reversal and R1-state lifetime, at 10 K, the pressure-dependent variation of mixing-degree of |t2^2(^3T1)e^4T2) and |t2^32E〉 base-wavefunetions in ...As a key factor leading to the pressure-dependent R1-line-shift reversal and R1-state lifetime, at 10 K, the pressure-dependent variation of mixing-degree of |t2^2(^3T1)e^4T2) and |t2^32E〉 base-wavefunetions in the wavefunction of R1 state of LLGG:Cr^3+ has been calculated and analyzed. From this, the physical origin of the pressure-dependent R1-line-shift reversal has been revealed. Furthermore, by using the pressure-dependent values of the sum of all square mixlng-coefficients of |t2^2 (^3T1)e^4T2〉 in the wavefunction of R1 state, the lifetimes of R1 state of LLG G:Cr^3+ at various pressures have been calculat, ed, which arc in good agreement with observed results. The quantum anticrossing effect between t2^32E and t2^2 (^3T1)e^4T2 levels due to both spin-orbital interaction and electron-phonon interaction is remarkable, which is related to the admixture of |t2^2(^3T1)e^4T2) and |t2^32E〉 as well as the low high crystal-field transition.展开更多
By means of both the theory for pressure-induced Shifts (PS) of energy spectra and the theory for shifts of energy spectra due to electron-phonon interaction (EPI), the normal-pressure energy spectra of α and β ...By means of both the theory for pressure-induced Shifts (PS) of energy spectra and the theory for shifts of energy spectra due to electron-phonon interaction (EPI), the normal-pressure energy spectra of α and β centers of Cr^3+ ions for LLGG:Cr^3+ and the PS's of R1 lines and U band of these centers have been calculated at 10 K, respectively. The total calculated results are in very good agreement with the experimental data. For LLGG:Cr^3+, the pressureinduced low-high crystal-field transition and the reversal of R1-line PS take place. The pressure-dependent variation of Rmix^ei (2E - 4T2) [mixing-degree of (t2^2 (^3T1)e^4T2) and (t2^3 E) base-wavefunctions in the wavefunction of R1 state without EPI] plays a key role for the reversal of R1-line PS. The behavior of the pure electronic PS of R1 line is quite different from that of the PS of R1 line due to EPI. It is the combined effect of them that gives rise to the total PS of R1 line. The comparison between R1-line PS's of GSGG:Cr^3+ and LLGG:Cr^3+ has been made. It is found that a peak of R1-line PS appears at Rmix^ei (^2E - ^4T2) ≈ 0.08.展开更多
文摘As a key factor leading to the pressure-dependent R1-line-shift reversal and R1-state lifetime, at 10 K, the pressure-dependent variation of mixing-degree of |t2^2(^3T1)e^4T2) and |t2^32E〉 base-wavefunetions in the wavefunction of R1 state of LLGG:Cr^3+ has been calculated and analyzed. From this, the physical origin of the pressure-dependent R1-line-shift reversal has been revealed. Furthermore, by using the pressure-dependent values of the sum of all square mixlng-coefficients of |t2^2 (^3T1)e^4T2〉 in the wavefunction of R1 state, the lifetimes of R1 state of LLG G:Cr^3+ at various pressures have been calculat, ed, which arc in good agreement with observed results. The quantum anticrossing effect between t2^32E and t2^2 (^3T1)e^4T2 levels due to both spin-orbital interaction and electron-phonon interaction is remarkable, which is related to the admixture of |t2^2(^3T1)e^4T2) and |t2^32E〉 as well as the low high crystal-field transition.
文摘By means of both the theory for pressure-induced Shifts (PS) of energy spectra and the theory for shifts of energy spectra due to electron-phonon interaction (EPI), the normal-pressure energy spectra of α and β centers of Cr^3+ ions for LLGG:Cr^3+ and the PS's of R1 lines and U band of these centers have been calculated at 10 K, respectively. The total calculated results are in very good agreement with the experimental data. For LLGG:Cr^3+, the pressureinduced low-high crystal-field transition and the reversal of R1-line PS take place. The pressure-dependent variation of Rmix^ei (2E - 4T2) [mixing-degree of (t2^2 (^3T1)e^4T2) and (t2^3 E) base-wavefunctions in the wavefunction of R1 state without EPI] plays a key role for the reversal of R1-line PS. The behavior of the pure electronic PS of R1 line is quite different from that of the PS of R1 line due to EPI. It is the combined effect of them that gives rise to the total PS of R1 line. The comparison between R1-line PS's of GSGG:Cr^3+ and LLGG:Cr^3+ has been made. It is found that a peak of R1-line PS appears at Rmix^ei (^2E - ^4T2) ≈ 0.08.