Volume 117, Issue 8, 22 August 2002
Index of content:
117(2002); http://dx.doi.org/10.1063/1.1501128View Description Hide Description
The core-ionization spectra of mixed Be-Mg clusters are computed by accurate ab initio methods. They are found to exhibit a variety of strong and unexpected effects originating from the presence of neighboring atoms of the same (native) or the other (foreign) element. The spectra reveal unusually low-lying intense satellites and the band shapes are sensitive to the local environment of the core-ionized atom. Foreign and native screening processes compete with each other resulting in specific spectral features which uniquely characterize the clusters.
117(2002); http://dx.doi.org/10.1063/1.1501476View Description Hide Description
Small spherical guest particles added to a nematic liquid-crystalline dispersion of colloidal rods self-assemble linearly into chain-like aggregates. We argue that the formation of these chains is induced by the excluded-volume coupling of the globules to the nematic matrix, and that pretransitional fluctuations in the mixture give rise to the structural reorganization of the linear aggregates observed in experiment. Ultimately, the repulsive interactions between the globules and the rods either promote large-scale demixing or a transition to a microphase-separated lamellar state, depending on the concentration of rods in the host dispersion.