Infrared vibrations in LaSrGaO4 and LaSrAlO4

Authors
Humlicek, J Henn, R Cardona, M
Citation
J. Humlicek et al., Infrared vibrations in LaSrGaO4 and LaSrAlO4, PHYS REV B, 61(21), 2000, pp. 14554-14563
Citations number
30
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
PHYSICAL REVIEW B
ISSN journal
01631829 → ACNP
Volume
61
Issue
21
Year of publication
2000
Pages
14554 - 14563
Database
ISI
SICI code
0163-1829(20000601)61:21<14554:IVILAL>2.0.ZU;2-S
Abstract
We have studied the c-axis and the in-plane infrared response of the anisot ropic crystals of LnSrGaPO(4) and LaSrAlO4. We identify both transverse and longitudinal phonons. The lattice bands show pronounced features of mode c oupling, which we attribute to the random distribution of La and Sr atoms i n the lattice. We present a scheme to identify and quantify the coupling th at induces the asymmetric line shapes. We use the results to discuss infrar ed-active vibrations of other compounds, including La2CuO4.