Altered photoemission satellites atCaF2- andSrF2-on-Si(111) int

Abstract

Bulk and interface photoemission satellite excitations, measured with x-ray photoelectron spectroscopy and x-ray photoelectron diffraction, are compared for thick, thin, and monolayer films of CaF 2 and SrF 2 on Si͑111͒. Intrinsic satellites are observed for excitation of atoms in the first monolayer, both uncovered and at the buried interface, that differ from those associated with bulk atoms. For F 1s excitation, the bulk and interface satellites differ only in width and amplitude; for the cation core excitations ͑Ca 2p, Sr 3p, and Sr 3d͒, the observed excitation energies and intensities differ both from the equivalent bulk satellites and among the various core hole states. The results yield new information on the nature of the interface bonding, as well as on the origin of both bulk and interface satellites. Several models are considered, including differential screening, dielectric losses, crystal-field and multiplet effects, and interface excitation. The most likely explanation for the new cation satellites at the CaF 2 /Si͑111͒ ͓SrF 2 /Si͑111͔͒ interface is localized excitation of the interface bond, where the interface band gap is controlled by the collapse of the Ca 3d ͑Sr 4d͒ level in the presence of the Ca ͑Sr͒ core hole.

DNA dielectrophoresis: Theory and applications a review

“…Recent developments, however, show a trend in the theoretical studies of dielectric particle properties toward more complex particle shapes, such as rod-like "polyelectrolytes" (see for instance [29,31,68,69] 8 ), which may even be allowed to bend in order to mimic simple-model DNA [70,71]. Moreover, advances in simulation techniques and increased computer power nowadays allow simulating electrokinetic phenomena to such resolution that the mechanisms behind the dielectric response of single polyelectrolyte macromolecules to external electric fields can be studied even down to the molecular level [72,73]. For instance, in [32][33][34]74] ion distributions around DNA fragments have been computed using different simulation approaches, ranging from Brownian dynamics to all atom techniques.…”

Ionic states associated with extraction/infusion of Li ions at LiFePO4 thin film cathode surface

“…The ratio of the Fe 2p 3/2 ; Fe 2p 1/2 peak area intensity increases as the number of charge–discharge cycles increases. This increase is explained by F 1s energy‐loss peaks, which are included in the Fe 2p 3/2 region . In addition, for ‘C’ (charged LiFePO 4 thin film) and ‘CDC’ (LiFePO 4 thin film performed charge after one cycle charge–discharge), the Fe 2p 1/2 peaks lie approximately 1 eV toward higher binding energy than those for A450 and ‘CD’ (LiFePO 4 thin film performed one cycle charge–discharge) in binding energy.…”

Electrophoretic mobilities of neutral analytes and electroosmotic flow markers in aqueous solutions of Hofmeister salts

“…5 and 6). Thanks to the fact that an underlying theory is available [9,37], we can then rationalize measurable mobility coefficients in terms of the microscopic structure of the solution next to the neutral solute. We can thus translate the excess or depletion of ions (or equally the charge in the ionic atmosphere) in the nearest several layers of the solvent around the solute into the resulting electrophoretic mobility.…”

“…In this study, we demonstrate by CE that two common EOF markers, thiourea (TUR), and DMSO, have indeed different electrophoretic mobilities, and provide a detailed interpretation of this effect using atomistic molecular dynamics (MD) simulations. In this context, we stress that in the present work we focus on atomistic details behind the electrophoretic mobilization rather than on multiscale approaches toward simulation at the continuum BGE level [9].…”