Probing interface localization–delocalization transitions by colloids

Shape-driven solid-solid transitions in colloids.

Solid-solid phase transitions are the most ubiquitous in nature, and many technologies rely on them. However, studying them in detail is difficult because of the extreme conditions (high pressure/temperature) under which many such transitions occur and the high-resolution equipment needed to capture the intermediate states of the transformations. These difficulties mean that basic questions rem...

Interface identification by non-local autoionization transitions.

We use an autoionization process that involves ultrafast energy transfer to neighbouring sites to characterize the formation of NeAr van der Waals bonds in clusters formed by a coexpansion of both gases. This autoionization process, the so-called interatomic or intermolecular coulombic decay (ICD), is ubiquitous in weakly bonded systems. The energy of the electron being emitted in the ICD proce...

Probing electronic transitions in individual carbon nanotubes by Rayleigh scattering.

Rayleigh scattering spectra were obtained from individual single-walled carbon nanotubes with the use of a laser-generated visible and near-infrared supercontinuum. This diagnostic method is noninvasive and general for nanoscale objects. The approach permits clear identification of excited states in arbitrary metallic and semiconducting nanotubes. We analyzed spectral lineshapes in relation to ...

Probing structural and dynamical transitions in polymer globules by force.

The dynamics of proteins and biopolymers play a crucial role in their function. By using Brownian dynamics we show that polymer globules, which serve as a model system for proteins, undergo a size-dependent dynamical transition from a liquid-like state at high T to a frozen state at low T with a relaxation time that diverges at the transition point. Furthermore, a stretch-induced melting transi...

Probing the Organic-mineral Interface