Linear wave vector dependence of low-frequency Raman modes in two uniaxialgyrotropic quartz-type materials: alpha-GaPO4 and alpha-AlPO4

Authors
Pinan-Lucarre, JP Ouillon, R Ranson, P
Citation
Jp. Pinan-lucarre et al., Linear wave vector dependence of low-frequency Raman modes in two uniaxialgyrotropic quartz-type materials: alpha-GaPO4 and alpha-AlPO4, CHEM P LETT, 302(1-2), 1999, pp. 164-170
Citations number
21
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
CHEMICAL PHYSICS LETTERS
ISSN journal
00092614 → ACNP
Volume
302
Issue
1-2
Year of publication
1999
Pages
164 - 170
Database
ISI
SICI code
0009-2614(19990312)302:1-2<164:LWVDOL>2.0.ZU;2-0
Abstract
Linear wave vector dependence of low-frequency E modes was investigated in two quartz-type materials: alpha-GaPO4 and alpha-AlPO4. It was found that t he splitting of doubly degenerate optical E-modes caused by spatial dispers ion is similar to that previously measured for the 132 cm(-1) E-mode in alp ha-quartz by Pine and Dresselhaus. Somewhat surprisingly, spatial dispersio n does not occur for all E-modes studied. This behaviour is discussed in te rms of the different origin of these modes. (C) 1999 Elsevier Science B.V. All rights reserved.