SURFACES OF CD(S,SE) NANOPARTICLES BY SMALL-ANGLE X-RAY-SCATTERING

A dilute system of CdSxSe1-x nanocrystals has been studied by means of small-angle X-ray scattering. Information about the surface state has been obtained, taking advantage of the large-q part of the scattering curve. The presence of edges at the surface of the nanoparticles is e videnced by the limit at zero of the chord-distribution function. On t he other hand, the information obtained from the high-q part of the sc attering curve is compared to that deduced from the whole spectrum. Th is comparison shows that a polyhedral model is needed to account for t he surface of the scattering particles. The particle-size distribution , evaluated assuming edged particles, is in good agreement with the ex pected distribution and yields a satisfactory simulated spectrum. Some properties of the particle structure can be suggested from the presen ce of the edges.