Abstract
The phonon properties of partially CuPtB-ordered Ga0.52In0.48P with degrees of ordering η=0,0.19,0.28,0.35,0.47 determined from generalized ellipsometry measurement of the near-band-gap order birefringence, are studied by far-infrared spectroscopic ellipsometry. We determine precise spectra of the anisotropic dielectric functions. With increasing η all Ga0.52In0.48P phonon modes split in E- and A1-type vibrations with polarization perpendicular and parallel to the sublattice ordering direction, respectively, and the mode frequencies shift continuously. We demonstrate here that the alloy-induced modes previously observed in highly disordered Ga0.52In0.48P [Phys. Rev. B 64, 155206 (2001)] have their origin in the ordered atomic arrangement of alike group-III atoms. We propose far-infrared dielectric anisotropy as a sensitive measure for sublattice ordering in multinary III-V alloys.
| Original language | English (US) |
|---|---|
| Article number | 195204 |
| Pages (from-to) | 1952041-19520410 |
| Number of pages | 17568370 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 66 |
| Issue number | 19 |
| State | Published - Nov 15 2002 |
| Externally published | Yes |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics