Comment on "Phonon modes in spontaneously ordered GaInP2 studied by micro-Raman scattering measurements" - art. no. 247201

The Raman intensity of optical phonons of spontaneously ordered GaInP2 is a nalyzed using the bond polarizability model. The results are compared with experimental data and with the assignments of the ordering-induced phonons by Cheong et al. [phys. Rev. B 56, 1888 (1997)]. It is shown that the ident ification of the Raman band at 354 cm(-1) as an ordering-induced AI longitu dinal mode polarized along the [(1) over bar 11] direction for (001) right- angle scattering geometry, made by Cheong et al, is inconsistent with the R aman selection rules; for GaInP2. It is shown that the 354-cm(-1) Raman ban d can instead be attributed to phonons polarized along the [(1) over bar 10 ] direction. Such phonons cannot exist in the perfectly ordered GaInP2 and can be attributed to the vibrations of the antiphase boundaries.