Scientific Highlights
Plasma interactions determine the composition in pulsed laser deposited thin films
Plasma chemistry and scattering strongly affect the congruent, elemental transfer during pulsed laser deposition of target metal species in an oxygen atmosphere. Studying the plasma properties of La0.6Sr0.4MnO3, we demonstrate for as grown La0.6Sr0.4MnO3-δ films that a congruent transfer of metallic species is achieved in two pressure windows: ∼10−3 mbar and ∼2 × 10−1 mbar.
Mixed Dimensionality of Confined Conducting Electrons in the Surface Region of SrTiO3
Using angle-resolved photoemission spectroscopy, we show that the recently discovered surface state on SrTiO3 consists of nondegenerate t2g states with different dimensional characters.
A revealing mixture: The surface of an oxide insulator can host two distinct types of conducting electrons
Strontium titanate, SrTiO3, is an important material for the realization of next-generation electronic devices. A famous example is the interface of LaAlO3 grown on SrTiO3, which is metallic and magnetic at its interface, even though the individual compounds are insulating and nonmagnetic in bulk form. The physics behind how novel interface states form on SrTiO3 - and how they become endowed with such surprising properties - is not well understood.
Spin-lattice coupling induced weak dynamical magnetism in EuTiO3 at high temperatures
EuTiO3, which is a G-type antiferromagnet below TN = 5.5 K, has some fascinating properties at high temperatures, suggesting that macroscopically hidden dynamically fluctuating weak magnetism exists at high temperatures. This conjecture is substantiated by magnetic field dependent magnetization measurements, which exhibit pronounced anomalies below 200 K becoming more distinctive with increasing magnetic field strength. Additional results from muon spin rotation experiments provide evidence for weak fluctuating bulk magnetism induced by spin-lattice coupling which is strongly supported in increasing magnetic field.
Low-Temperature Micro-Solid Oxide Fuel Cells with Partially Amorphous La0.6Sr0.4CoO3-δ Cathodes
Partially amorphous La0.6Sr0.4CoO3-δ (LSC) thin-film cathodes are fabricated using pulsed laser deposition and are integrated in free-standing micro-solid oxide fuel cells (micro-SOFC) with a 3YSZ electrolyte and a Pt anode. A low degree of crystallinity of the LSC layers is achieved by taking advantage of the miniaturization of the cells, which permits low-temperature operation (300–450 °C).
Correlated Decay of Triplet Excitations in the Shastry-Sutherland Compound SrCu2(BO3)2
The temperature dependence of the gapped triplet excitations (triplons) in the 2D Shastry-Sutherland quantum magnet SrCu2(BO3)2 is studied by means of inelastic neutron scattering. The excitation amplitude rapidly decreases as a function of temperature, while the integrated spectral weight can be explained by an isolated dimer model up to 10 K.
Fast scanning coherent X-ray imaging using Eiger
The smaller pixel size, high frame rate, and high dynamic range of next-generation photon counting pixel detectors expedites measurements based on coherent diffractive imaging (CDI). The latter comprises methods that exploit the coherence of X-ray synchrotron sources to replace imaging optics by reconstruction algorithms. Researchers from the Paul Scherrer Institut have recently demonstrated fast CDI image acquisition above 25,000 resolution elements per second using an in-house developed Eiger detector. This rate is state of the art for diffractive imaging and even on a par with the fastest scanning X-ray transmission instruments. High image throughput is of crucial importance for both materials and biological sciences for studies with representative population sampling.
Square dance of the atoms: Shedding light on ultrafast phase transitions
The exploration of the interaction of structural and electronic degrees of freedom in strongly correlated electron systems on the femtosecond time scale is an emerging area of research. One goal of these studies is to advance our understanding of the underlying correlations, another to find ways to control the exciting properties of these materials on an ultrafast time scale.
Square dance of the atoms: Shedding light on ultrafast phase transitions
The exploration of the interaction of structural and electronic degrees of freedom in strongly correlated electron systems on the femtosecond time scale is an emerging area of research. One goal of these studies is to advance our understanding of the underlying correlations, another to find ways to control the exciting properties of these materials on an ultrafast time scale. So far a general model is lacking that provides a quantitiative description of the correlations between the structural and electronic degrees of freedom.
Negative Oxygen Isotope Effect on the Static Spin Stripe Order in Superconducting La2−xBaxCuO4(x=1/8) Observed by Muon-Spin Rot
Large negative oxygen-isotope (16O and 18O) effects (OIEs) on the static spin-stripe-ordering temperature Tso and the magnetic volume fraction Vm were observed in La2−xBaxCuO4(x=1/8) by means of muon-spin-rotation experiments. The corresponding OIE exponents were found to be αTso=-0.57(6) and αVm=-0.71(9), which are sign reversed to αTC=0.46(6) measured for the superconducting transition temperature Tc. This indicates that the electron-lattice interaction is involved in the stripe formation and plays an important role in the competition between bulk superconductivity and static stripe order in the cuprates.