Raman spectroscopy of oxides of GaAs formed in solution

Electrochemical treatment of crystalline GaAs in 1 M HCl results in the for mation of porous GaAs. As a by-product of the electrochemical dissolution p rocess, small transparent crystals may grow on the porous GaAs skeleton und er certain chemical conditions. These surface crystalline deposits have bee n investigated by Raman scattering spectroscopy. From surface chemical anal ysis and by reference to the Raman spectra of appropriate chemical compound s, it was determined that the crystallites comprise As2O3 and Ga2O3. Their Raman spectra and that of As2O5. xH(2)O are presented here for the first ti me in detail.