Surface phonon-polaritons in slabs of polar ternary mixed crystals are investigated with the modified random-element-isodisplacement model and the Born-Huang approximation, based on Maxwell＇s equations with the usual...Surface phonon-polaritons in slabs of polar ternary mixed crystals are investigated with the modified random-element-isodisplacement model and the Born-Huang approximation, based on Maxwell＇s equations with the usual boundary conditions. The numerical results of the surface phonon-polariton frequencies as functions of the wave-vector and thickness for slabs of ternary mixed crystals AlxGa1-xAs, Znx Cd1-x S,and Gax In1-x N are obtained and discussed. It is shown that there are four branches of surface phonon-polaritons in slab systems. The “two-mode” and “one-mode” behaviors of surface phonon-polaritons are also shown in their dispersion curves.展开更多
In this paper the bulk exciton polaritons in ternary mixed crystals （TMCs） are investigated in the Born-Huang approximation. The numerical results of the polariton frequencies as functions of the wave-vector and the...In this paper the bulk exciton polaritons in ternary mixed crystals （TMCs） are investigated in the Born-Huang approximation. The numerical results of the polariton frequencies as functions of the wave-vector and the compositions for ternary mixed crystals AlxGa1-xAs, CdxZn1-xSe, and AlxGa1-xN are obtained and discussed. The new dispersion characteristics for exciton-polaritons in TMC systems are found in comparison with binary crystals. The splitting of the two branches of exciton-polariton frequencies varies nonlinearly with the composition of TMCs and has a minimum in the long-wavelength range.展开更多
The interface phonon-polaritons in quantum well systems consisting of polar ternary mixed crystals are investi-gated. The numerical results of the interface phonon-polariton frequencies in the GaAs/AlxGa1-xAs, ZnSxSe1...The interface phonon-polaritons in quantum well systems consisting of polar ternary mixed crystals are investi-gated. The numerical results of the interface phonon-polariton frequencies in the GaAs/AlxGa1-xAs, ZnSxSe1-x/ZnS, and ZnxCd1-xSe/ ZnSe quantum well systems are obtained and discussed. It is shown that there are six branches of interface phonon-polariton modes distributed in three bulk phonon-polariton forbidden bands in the systems. The electric fields of interface phonon polaritons are also presented and show the interface locality of the modes. The effects of the ＇two-mode＇ and ＇one-mode＇ behaviours of the ternary mixed crystals on the interface phonon-polariton modes are shown in the dispersion curves.展开更多
The stability constants of the ternary M(Bic)(Bzim)+ complexes, where M2+ = Cu2+, Ni2+ or Zn2+, Bic- = the anion of N, N-bis(2-hydroxyethyl) glycine and Bzim = benzimidazole, were determined by potentiometric pH titra...The stability constants of the ternary M(Bic)(Bzim)+ complexes, where M2+ = Cu2+, Ni2+ or Zn2+, Bic- = the anion of N, N-bis(2-hydroxyethyl) glycine and Bzim = benzimidazole, were determined by potentiometric pH titration in aqueous solution. One of them (M2+ = Cu2+) was also separately determined by spectrophotometry. The results show that these ternary complexes are stabler than expected on statistical grounds. The enhanced stability of the ternary M(Bic) (Bzim)+ complexes is attributed to the πA-πB cooperative effect between Bic- and benzimidazole. Besides, compared with Cu(Bic) (Bzim)+ and Ni(Bic) (Bzim)+, the ternary Zn(Bic) (Bzim)+ complex has relatively high stability. The crystal structure of [Cu(Bic)(Bzim)]ClO4 was determined by single crystal X-ray diffraction techniques. The copper atom has a trigonal-bipyramidal geometry, the basal plane is formed by an oxygen atom of the carboxylato group and two hydroxyl oxygen atoms, the apical position is occupied by a nitrogen atom of Bic- and a nitrogen atom of benzimidazole. The molecular structure of Cu(Bic) (Bzim)+ in aqueous solution is different from that in the crystalline state. The results of ESR and electronic spectra show that the structure of this complex is octahedron in aqueous solution.展开更多
文摘Surface phonon-polaritons in slabs of polar ternary mixed crystals are investigated with the modified random-element-isodisplacement model and the Born-Huang approximation, based on Maxwell＇s equations with the usual boundary conditions. The numerical results of the surface phonon-polariton frequencies as functions of the wave-vector and thickness for slabs of ternary mixed crystals AlxGa1-xAs, Znx Cd1-x S,and Gax In1-x N are obtained and discussed. It is shown that there are four branches of surface phonon-polaritons in slab systems. The “two-mode” and “one-mode” behaviors of surface phonon-polaritons are also shown in their dispersion curves.
基金Project supported partly by PhD Progress Foundation of Higher Education Institutions of China （Grant No 20040126003） and the Natural Science Foundation of Inner Mongol of China （Grant No 200408020101）.
文摘In this paper the bulk exciton polaritons in ternary mixed crystals （TMCs） are investigated in the Born-Huang approximation. The numerical results of the polariton frequencies as functions of the wave-vector and the compositions for ternary mixed crystals AlxGa1-xAs, CdxZn1-xSe, and AlxGa1-xN are obtained and discussed. The new dispersion characteristics for exciton-polaritons in TMC systems are found in comparison with binary crystals. The splitting of the two branches of exciton-polariton frequencies varies nonlinearly with the composition of TMCs and has a minimum in the long-wavelength range.
基金supported partly by the National Natural Science Foundation of China (Grant Nos.10764003 and 10947179)
文摘The interface phonon-polaritons in quantum well systems consisting of polar ternary mixed crystals are investi-gated. The numerical results of the interface phonon-polariton frequencies in the GaAs/AlxGa1-xAs, ZnSxSe1-x/ZnS, and ZnxCd1-xSe/ ZnSe quantum well systems are obtained and discussed. It is shown that there are six branches of interface phonon-polariton modes distributed in three bulk phonon-polariton forbidden bands in the systems. The electric fields of interface phonon polaritons are also presented and show the interface locality of the modes. The effects of the ＇two-mode＇ and ＇one-mode＇ behaviours of the ternary mixed crystals on the interface phonon-polariton modes are shown in the dispersion curves.
基金Project supported by the National Natural Science Foundation of China (Grant No. 29871036)the Natural Science Foundation of Guangdong Province (Grant No. 97021)the State Key Laboratory of Coordination Chemistry of Nanjing University
文摘The stability constants of the ternary M(Bic)(Bzim)+ complexes, where M2+ = Cu2+, Ni2+ or Zn2+, Bic- = the anion of N, N-bis(2-hydroxyethyl) glycine and Bzim = benzimidazole, were determined by potentiometric pH titration in aqueous solution. One of them (M2+ = Cu2+) was also separately determined by spectrophotometry. The results show that these ternary complexes are stabler than expected on statistical grounds. The enhanced stability of the ternary M(Bic) (Bzim)+ complexes is attributed to the πA-πB cooperative effect between Bic- and benzimidazole. Besides, compared with Cu(Bic) (Bzim)+ and Ni(Bic) (Bzim)+, the ternary Zn(Bic) (Bzim)+ complex has relatively high stability. The crystal structure of [Cu(Bic)(Bzim)]ClO4 was determined by single crystal X-ray diffraction techniques. The copper atom has a trigonal-bipyramidal geometry, the basal plane is formed by an oxygen atom of the carboxylato group and two hydroxyl oxygen atoms, the apical position is occupied by a nitrogen atom of Bic- and a nitrogen atom of benzimidazole. The molecular structure of Cu(Bic) (Bzim)+ in aqueous solution is different from that in the crystalline state. The results of ESR and electronic spectra show that the structure of this complex is octahedron in aqueous solution.
