Pyroelectrically-driven chemical reactions described by a novel thermodynamic cycle.

Pyroelectrocatalysis is the conversion of thermal energy directly into chemical energy. On the background of renewable energies and the need for efficient industrial processes, the conversion of waste heat into hydrogen is of special relevance. Since the reported thermodynamic cycles for pyroelectric energy harvesting do not fit the conditions encountered in a reactive medium such as water appropriately, we describe a new thermodynamic charge-voltage-cycle characterised by fixed upper and lower potentials.

Formation of Thin NiGe Films by Magnetron Sputtering and Flash Lamp Annealing.

The nickel monogermanide (NiGe) phase is known for its electrical properties such as low ohmic and low contact resistance in group-IV-based electronics. In this work, thin films of nickel germanides (Ni-Ge) were formed by magnetron sputtering followed by flash lamp annealing (FLA). The formation of NiGe was investigated on three types of substrates: on amorphous (a-Ge) as well as polycrystalline Ge (poly-Ge) and on monocrystalline (100)-Ge (c-Ge) wafers.

Picometer polar atomic displacements in strontium titanate determined by resonant X-ray diffraction.

Physical properties of crystalline materials often manifest themselves as atomic displacements either away from symmetry positions or driven by external fields. Especially the origin of multiferroic or magnetoelectric effects may be hard to ascertain as the related displacements can reach the detection limit. Here we present a resonant X-ray crystal structure analysis technique that shows enhanced sensitivity to minute atomic displacements.

The anisotropy of oxygen vacancy migration in SrTiO.

Oxygen migration in perovskites is well known to occur via vacancies along the TiO octahedron edges. Ionic conduction depends further on the orientation of the crystal in the electric field. To study the anisotropy in cubic SrTiO single crystals, temperature-dependent electroformation measurements ranging from 11 °C to 50 °C have been conducted for representative crystallographic directions within the crystal system.