Scientific Highlights

Magnetism has been predicted to occur in systems in which dipolar interactions dominate exchange. We present neutron scattering, specific heat, and magnetic susceptibility data for LiErF₄, establishing it as a model dipolar-coupled antiferromagnet with planar spin-anisotropy and a quantum phase transition in applied field H_c|| = 4.0 ± 0.1 kilo-oersteds.

he optimization of thermochemical and electrochemical conversion systems is of high importance for a sustainable energy future society. Of particular interest regarding the performance of polymer electrolyte fuel cells (PEFCs) is the study of the gas flow in the gas diffusion layers (GDL). More specifically, permeability and diffusivity measurements in a model PEFC under normal operating conditions are highly desirable. As laboratory-measurements of these quantities under such conditions are very demanding, an alternative is the use of computer-based simulations.

Human activities have significantly altered atmospheric Pb concentrations and thus, its geochemical cycle, for thousands of years. Whereas historical Pb emissions from Western Europe, North America, and Asia are well documented, there is no equivalent data for Eastern Europe. Here, we present ice-core Pb concentrations for the period 1680à1995 from Belukha glacier in the Siberian Altai, assumed to be representative of emissions in Eastern Europe and the Altai.

An optimized laser-induced forward transfer (LIFT) technique has been used to fabricate tri-color organic light-emitting diode (OLED) pixels. At reduced pressures, and with a defined donor-receiver gap, patterned depositions of polyfluorene-based OLED pixels have been achieved. OLED pixel functionality has been demonstrated and compared with devices made using conventional deposition techniques. In addition, improved functionality has been obtained by coating the cathode with an electron-injecting layer, a process not possible using conventional OLED fabrication techniques. The OLED pixels fabricated by LIFT reach efficiencies on the range of conventionally fabricated devices and even surpass them in the case of blue pixels.

In many heavy fermion materials the quantum critical point is masked by superconductivity and it can only be detected by use of a local probe. In the noncentrosymmetric heavy fermion CeRhSi₃ the ground state at ambient pressure is antiferromagnetically ordered and superconductivity sets in above 12 kbar coexisting with antiferromagnetism. We have unraveled a magnetic quantum critical point hidden deep inside the superconducting state of CeRhSi₃.

In the emerging field of spintronics, the generation, injection, and in particular the control of highly spin polarized currents are main issues to be solved. Lifting of spin degeneracy by the spin-orbit interaction at surfaces, known as Rashba effect, represents a promising approach, since it generates two spin-polarized bands without the necessity of an external field. In our recent study, we realize such a system for a metallic surface layer on a semiconductor: Au/Ge(111).

An electron has been observed to decay into two separate parts, each carrying a particular property of the electron: a spinon carrying its spin – the property making the electron behave as a tiny compass needle – and an orbiton carrying its orbital moment – which arises from the electron’s motion around the nucleus. These newly created particles, however, cannot leave the material in which they have been produced.

We report on the synthesis and characterization of multiresponsive hybrid microgel particles. The particles consist of ellipsoidal silica-coated maghemite cores subsequently coated with thermoresponsive poly (N-isopropylacrylamide) (PNIPAM) shells. The PNIPAM shell enables the hybrid particle to alter its size and ratio of long to small axis with increasing temperature while the core morphology remains unchanged.

Researchers at the Paul Scherrer Institute are finding out how long it takes to establish magnetism and how this happens.

We use time-resolved x-ray diffraction and magneto-optical Kerr effect to study the laser-induced antiferromagnetic to ferromagnetic phase transition in FeRh. The structural response is given by the nucleation of independent ferromagnetic domains (t ~ 30 ps).