We report the observation of tunneling anisotropic magnetoresistance (TAMR) in an organic spin-valve-like structure with only one ferromagnetic electrode. The device is based on a new high mobility perylene diimide-based n-type organic semiconductor. The effect originates from the tunneling injection from the LSMO contact and can thus occur even for organic layers which are too thick to support the assumption of tunneling through the layer. Magnetoresistance measurements show a clear spin-valve signal, with the typical two step switching pattern caused by the magnetocrystalline anisotropy of the epitaxial magnetic electrode.Comment: 10 pages 5 figures Paper has been rewritten, new results have been adde

We report on the first observation of an approximant structure to the recently discovered two-dimensional oxide quasicrystal. Using scanning tunneling microscopy, low-energy electron diffraction, and surface x-ray diffraction in combination with ab initio calculations, the atomic structure and the bonding scheme are determined. The oxide approximant follows a 3^{2}.4.3.4 Archimedean tiling. Ti atoms reside at the corners of each tiling element and are threefold coordinated to oxygen atoms. Ba atoms separate the TiO_{3} clusters, leading to a fundamental edge length of the tiling 6.7 Å.

We report on the formation of a SrTiO-derived dodecagonal oxide quasicrystal (OQC) at the interface to Pt(1 1 1). This is the second observation of a two-dimensional quasicrystal in the class of oxides. The SrTiO-derived OQC exhibits strong similarities to the BaTiO-derived OQC with respect to the local tiling geometry. However, the characteristic length scale of the SrTiO-derived OQC is 1.8% smaller. Coexisting with the OQC a large scale approximant structure with a monoclinic unit cell is identified. It demonstrates the extraordinary level of complexity that oxide approximant structures can reach.

The combination of gasoline direct injection and turbocharging is a promising method to reduce the fuel consumption of internal combustion engines through engine downsizing, which leads to increased engine efficiencies and a reduction of CO2 emissions at a comparable power output. Spray-guided direct injection allows overall lean and unthrottled operation, which is realized with a highly stratified mixture at part load. However, exhaust gas aftertreatment with conventional three-way catalysts is currently not possible. Furthermore, insufficient mixture preparation, especially at the upper load limit of stratified charge operation, causes increased particulate matter emissions. This paper discusses the advantages of engine downsizing, by gasoline direct injection in combination with turbocharging, to reduce fuel consumption and presents the results of experimental and numerical investigations of stratified exhaust gas recirculation in a single-cylinder gasoline engine to reduce nitrogen oxide emissions. The radial exhaust gas stratification was achieved by a spatial and temporal separated induction of exhaust gas and fresh air, performed by specially shaped baffles and impulse charge valves in the inlet port. The thermodynamic and optical investigations with injection pressures up to 1000 bar demonstrate the capability to reduce soot emissions in a spray-guided direct-injection engine.

The recently discovered two-dimensional oxide quasicrystal (OQC) derived from BaTiO 3 on Pt(111) is the first material in which a spontaneous formation of an aperiodic structure at the interface to a periodic support has been observed. Herein, we report in situ low-energy electron microscopy (LEEM) studies on the fundamental processes involved in the OQC growth. The OQC formation proceeds in two steps via of an amorphous two-dimensional wetting layer. At 1170 K the long-range aperiodic order of the OQC develops. Annealing in O 2 induces the reverse process, the conversion of the OQC into BaTiO 3 islands and bare Pt(111), which has been monitored by in situ LEEM. A quantitative analysis of the temporal decay of the OQC shows that oxygen adsorption on bare Pt patches is the rate limiting step of this dewetting process.