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The evolution of self-assembled CdSe quantum dots deposited on (and subsequently capped by) ZnSe was investigated on a series of samples grown by molecular beam epitaxy, with CdSe coverages from 0.5 to 2.6 monolayers. The samples were investigated by cross-sectional scanning transmission electron microscopy, as well as macro- and microphotoluminescence. The results clearly indicated a coexistence of 2D ZnCdSe platelets and 3D islands, showing clearly that the platelets act as precursors for the formation of the 3D islands.

We report here differences of — 10% in the values of the elastic constants of solid krypton near its triple point as determined by inelastic scattering of neutrons and by Brillouin scattering. These large differences are interpreted to be due to the dissimilar propagation speeds of zero and first sound in this temperature region of large anhar

Propagation of heat pulses in NaF has been studied to higher temperatures in a purer crystal than studied by McNelly et al. At the highest temperatures the second-sound velocity fails to level off at the theoretically predicted limiting value.

Strong quasielastic features have been found in light scattering from diamond in the frequency range 0 to \ifmmode\pm\else\textpm\fi{} 200 GHz and have been investigated as a function of wave-vector transfer ($Q$) and temperature ($T$). The evolution of a relatively narrow Lorentzian component (\ensuremath{\sim} 10 GHz) demonstrates for the first time the manner in which a two-phonon difference spectrum in the collision-free regime (low $T$ and large $Q$) develops into entropy-fluctuation scattering in the collision-dominated regime (high $T$ and low $Q$).