TY - JOUR
T1 - Far-Infrared dielectric anisotropy and phonon modes in spontaneously CuPt-ordered (formula presented)
AU - Hofmann, T.
AU - Gottschalch, V.
AU - Schubert, M.
PY - 2002
Y1 - 2002
N2 - The phonon properties of partially (formula presented)-ordered (formula presented) with degrees of ordering (formula presented)(formula presented)(formula presented)(formula presented)(formula presented) 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 (formula presented) all (formula presented) phonon modes split in E- and (formula presented)-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 (formula presented) [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.
AB - The phonon properties of partially (formula presented)-ordered (formula presented) with degrees of ordering (formula presented)(formula presented)(formula presented)(formula presented)(formula presented) 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 (formula presented) all (formula presented) phonon modes split in E- and (formula presented)-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 (formula presented) [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.
UR - http://www.scopus.com/inward/record.url?scp=85038309939&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85038309939&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.66.195204
DO - 10.1103/PhysRevB.66.195204
M3 - Article
AN - SCOPUS:85038309939
SN - 1098-0121
VL - 66
SP - 1
EP - 10
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 19
ER -