TY - JOUR
T1 - Detection of LO mode in v-SiO2 by infrared diffuse reflectance spectroscopy
AU - Almeida, Rui M.
AU - Guiton, Theresa A.
AU - Pantano, Carlo G.
N1 - Funding Information:
One of the.' authors (R.M.A.) wishes to acknowledge the financial support of the Junta Nacional de Investiga~o Cientifica e Tecnol6gica and the Funda~o Luso-Americana para o De-senvolvimento (Portugal) plus the National Academy of Sciences (USA), for their joint support of this work. The support of INESC (Portugal) is also acknowledgedT. .A.G. and C.G.P. thank the Office of Naval Research (N00014-86-K) for their support of this work.
PY - 1990/4/2
Y1 - 1990/4/2
N2 - It has been found that the high frequency longitudinal optical (LO) mode in vitreous SiO2 can be observed in the diffuse reflectance spectra of bulk glass or powder compacts. The sensitivity to this mode arises because of the off-normal components of reflectance which are collected in the diffuse reflectance spectra. The frequency and intensity of the mode are only approximately determined, however, and Kramers-Kronig transformation of specular reflectivity data is required to calculate precisely the mode location and intensity. The significance of this finding is that, in contrast to the use of infrared reflectance or Raman spectroscopy, where polished bulk specimens or single crystals are required, the present approach permits the determination of LO modes with with powder.
AB - It has been found that the high frequency longitudinal optical (LO) mode in vitreous SiO2 can be observed in the diffuse reflectance spectra of bulk glass or powder compacts. The sensitivity to this mode arises because of the off-normal components of reflectance which are collected in the diffuse reflectance spectra. The frequency and intensity of the mode are only approximately determined, however, and Kramers-Kronig transformation of specular reflectivity data is required to calculate precisely the mode location and intensity. The significance of this finding is that, in contrast to the use of infrared reflectance or Raman spectroscopy, where polished bulk specimens or single crystals are required, the present approach permits the determination of LO modes with with powder.
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U2 - 10.1016/0022-3093(90)90847-F
DO - 10.1016/0022-3093(90)90847-F
M3 - Letter
AN - SCOPUS:0025413859
SN - 0022-3093
VL - 119
SP - 238
EP - 241
JO - Journal of Non-Crystalline Solids
JF - Journal of Non-Crystalline Solids
IS - 2
ER -