Understanding the nature of charge carriers at the LaAlO3/SrTiO3 interface is one of the major open issues in the full comprehension of the charge confinement phenomenon in oxide heterostructures. Here, we investigate thermopower to study the electronic structure in LaAlO3/SrTiO3 at low temperature as a function of gate field. In particular, under large negative gate voltage, corresponding to t...

The polaron is a quasi-particle formed by a conduction electron (or hole) together with its self-induced polarization in a polar semiconductor or an ionic crystal. Among various polarizable examples of complex oxides, strontium titanate (SrTiO3) is one of the most studied. Here we examine the carrier type and the interplay of inner degrees of freedom (for example, charge, lattice, orbital) in S...

La0.7Sr0.3MnO3, a half-metallic ferromagnet with full spin polarization, is generally used as a standard spin injector in heterostructures. However, the magnetism of La0.7Sr0.3MnO3 is strongly modified near interfaces, which was addressed as "dead-layer" phenomenon whose origin is still controversial. Here, both magnetic and structural properties of La0.7Sr0.3MnO3/SrTiO3 heterostructures were i...

SrRuO3 films and SrRuO3/SrTiO3 superlattices grown on SrTiO3(001) were studied by structural, magnetic, magnetoresistance and Hall effect measurements. The superlattices showed heteroepitaxial growth with coherent interfaces and a Ru/Ti diffusion region of 1-1.5 unit cells. The resistivity had metallic character above a critical thickness of 3-4 unit cells, becoming insulating below. There was ...

Strontium titanate (SrTiO3) nanopowder has been synthesized through a sol-gelhydrothermal method. The X-ray diffraction studies of SrTiO3 nanopowder have shown that the asprepared powder was single phase, crystalline, and has a cubic perovskite structure (ABO3) with a lattice constant a = 3.903 Å. The particle size calculated from FWHM was ∼22 nm. SrTiO3 nanopowder was examined using thermo gra...

The reduction of oxides during annealing and growth in low pressure processes is a widely known problem. We hence investigate the influence of mere annealing and of growth in vacuum systems to shed light on the reasons behind the reduction of perovskites. When comparing the existing literature regarding the reduction of the perovskite model material SrTiO3 it is conspicuous that one finds diffe...

The early stages of nucleation and growth of atomic layer deposition (ALD) platinum on SrTiO3 (001) have been studied. Scanning electron microscopy reveals the ALD Pt deposits as discrete nanoparticles that grow and coalesce with increasing number of ALD cycles, ultimately resulting in a continuous film after ∼40 cycles. Atomic force microscopy shows the films to be fine-grained and highly conf...

We report results of first-principles density-functional studies of the atomic and electronic structure of Co/Al2O3 /Co and Co/SrTiO3 /Co magnetic tunnel junctions ~MTJs!. The atomic structure has been studied for different interface terminations and the interfacial energetics was quantified based on the work of separation. Based on energetics of cohesion, the O-terminated and TiO2-terminated i...

The metallic interface between insulating LaAlO3 and SrTiO3 opens up the field of oxide electronics. With more than a decade of researches on this heterostructure, the origin of the interfacial conductivity, however, remains unsettled. Here we resolve this long-standing puzzle by atomic-scale observation of electron-gas formation for screening hidden lattice instabilities, rejuvenated near the ...

Emerging electrical and magnetic properties of oxide interfaces are often dominated by the termination and stoichiometry of substrates and thin films, which depend critically on the growth conditions. Currently, these quantities have to be measured separately with different sophisticated techniques. This report will demonstrate that the analysis of angle dependent X-ray photoelectron intensity ...