DYNAMIC PROPERTIES OF GA1-XINXAS SOLID-SOLUTIONS - INFLUENCE OF LOCALDISTORTION EFFECTS

Polarization measurements on Raman spectra of Ga1-xInxAs solid solutio ns are performed over a wide energy range (10 cm-1 - 600 cm-1) for sev eral concentrations (x = 0, 0.09, 0.20, 0.40, 0.53, 1). They show that this system follows the so-called ''two-mode behaviour''. The predomi nance of the GaAs band in the Raman spectra and the large splitting of the two longwavelength optical GaAs modes over a large range of compo sition are correlated to the enhancement of the coupling between the t wo types of oscillators by local distortion effects.