摘要:

AbstractThe evolution of the internal and external modes in the Raman spectra of NaClO4has been studied in the neighbourhood of the transition temperature, at 581 K. Large changes in the frequencies of the external modes with temperature have been observed. These changes can be explained in terms of a model based on the reorientation of the perchlorate ions.

ISSN:0377-0486    

DOI:10.1002/jrs.1250070105

出版商:John Wiley&Sons, Ltd.    

年代:1978

数据来源: WILEY

摘要:

AbstractEvidence is presented, based on Raman scattering measurements, that the three modes observed in theA1(TO) phonon spectrum of tetragonal BaTiO3are first order. These results are interpreted as supporting the order‐disorder model of the ferroelectric phase transitio

ISSN:0377-0486    

DOI:10.1002/jrs.1250070106

出版商:John Wiley&Sons, Ltd.    

年代:1978

数据来源: WILEY

摘要:

AbstractThe general connections between Stokes and anti‐Stokes cross sections are examined on the basis of the time‐reversal symmetry of light‐scattering experiments. The corresponding symmetry properties of the transition rates, susceptibilities and Green functions which occur in light‐scattering theory are reviewed. A rigorous Stokes‐anti‐Stokes connection formula is derived and compared with an approximation in

ISSN:0377-0486    

DOI:10.1002/jrs.1250070107

出版商:John Wiley&Sons, Ltd.    

年代:1978

数据来源: WILEY

摘要:

AbstractTheEgvibration at 1268 cm−1of cyclohexane is investigated by Raman scattering near the phase transition at 186 K. Within an interval of 1.5 K below the phase transition this band is split into five components with changing intensities. The spectra confirm the existence of a metastable phase. From the site and factor group of the stable phase the assignment of the absorption band at 862 cm−1in the infrared spectrum is establis

ISSN:0377-0486    

DOI:10.1002/jrs.1250070108

出版商:John Wiley&Sons, Ltd.    

年代:1978

数据来源: WILEY

摘要:

AbstractInfrared and Raman spectra ofp‐chloroaniline are reported and assigned for the low‐frequency lattice region at 300 K and 78 K. The observed frequencies of the lattice modes are compared with those calculated using a semi‐empirical intermolecular potential. The agreement is very good, so confirming the high degree of transferability of the atom‐atom potentials. The equilibrium conditions are also well fulfilled by the potential. The total calculated crystal energy is −13.5 k

ISSN:0377-0486    

DOI:10.1002/jrs.1250070109

出版商:John Wiley&Sons, Ltd.    

年代:1978

数据来源: WILEY

摘要:

AbstractThe orientational dynamics is studied by the Raman spectrum of the ground state molecules S 2−and is found to be isotope selective. The Raman spectrum of S 2−molecules in the excited state2Πuand in another tentatively assigned state is p

ISSN:0377-0486    

DOI:10.1002/jrs.1250070110

出版商:John Wiley&Sons, Ltd.    

年代:1978

数据来源: WILEY

摘要:

AbstractThe second‐, third‐ and fourth‐order Raman spectra of GaP monocrystals have been investigated, and the relative intensities measured. It is found that the fourth‐order Raman maxima are only a little less intense (about 5 times) than the third‐order ones. Polariton scattering from GaP has also been investigated. It is found that the intensities of polariton scattering and second‐order scattering

ISSN:0377-0486    

DOI:10.1002/jrs.1250070111

出版商:John Wiley&Sons, Ltd.    

年代:1978

数据来源: WILEY

摘要:

AbstractThe lattice vibrational spectrum ofp‐nitrotoluene (PNT) single crystals has been studied by Raman and IR spectroscopic techniques. Twenty‐one lines have been recorded in the Raman spectrum and nine lines in the far IR spectrum. Calculations of vibrational frequencies have been performed using the rigid molecule approximation. Intermolecular interactions have been described by atom‐pair intermolecular potential functions for interatomic distances up to 4.0 Å. An assignment of the observed to the calculated frequencies has been pr

ISSN:0377-0486    

DOI:10.1002/jrs.1250070112

出版商:John Wiley&Sons, Ltd.    

年代:1978

数据来源: WILEY

摘要:

AbstractThe Raman spectra of solid complexes formed between halogens as electron donors and benzene and methylated benzenes as electron acceptors were measured at 77 K. Great increase in intensity was observed for the Raman lines ν10(e1g), ν16(e2u) and ν17(e2u) of benzene on complex formation. The great intensity enhancement of these out‐of‐plane bending modes is reasonably explained as the result of mixing of the1A2u(σπ*) state of benzene and the charge transfer state. The observed spectra are consistent with the crystal structure of factor groupC3ν, having one halogen molecule and one benzene molecule in a unit cell, which was proposed by Personet al.from the infrared spectra. It was found that the Raman spectra of the complexes provide a good test for the Raman intensity mechanism proposed for benzene and also give important information about electronic excited states which are not identifiable by ot

ISSN:0377-0486    

DOI:10.1002/jrs.1250070113

出版商:John Wiley&Sons, Ltd.    

年代:1978

数据来源: WILEY

摘要:

AbstractThe low‐frequency Raman spectrum (6–50 cm−1) of TbP5O14over the temperature range 300–620 K is reported and the behavior of the soft mode observed, is di

ISSN:0377-0486    

DOI:10.1002/jrs.1250070114

出版商:John Wiley&Sons, Ltd.    

年代:1978

数据来源: WILEY