Heterojunction Devices Fabricated from Sprayed -Type GaO, Combined with Sputtered -Type NiO and CuO.

This work reports on the properties of heterojunctions consisting of -type GaO layers, deposited using ultrasonic spray pyrolysis at high temperature from water-based solution, combined with -type NiO and CuO counterparts, deposited by radio frequency and reactive, direct-current magnetron sputtering, respectively. After a comprehensive investigation of the properties of the single layers, the fabricated junctions on indium tin oxide (ITO)-coated glass showed high rectification, with an open circuit voltage of 940 mV for GaO/CuO and 220 mV for GaO/NiO under simulated solar illumination. This demonstrates in praxis the favorable band alignment between the sprayed GaO and CuO, with small conduction band offset, and the large offsets anticipated for both energy bands in the case of GaO/NiO.

Tunability of silicon clathrate film properties by controlled guest-occupation of their cages.

Type I and type II silicon clathrates are guest-host structures made of silicon polyhedral cages large enough to contain atoms that can be either inserted or evacuated with only a slight volume change of the structure. This feature is of interest not only for batteries or storage applications but also for tuning the properties of the silicon clathrate films. The thermal decomposition process can be tuned to obtain Na8Si46 and Na2 View Article and Find Full Text PDF

Shallow implanted SiC spin qubits used for sensing an internal spin bath and external YIG spins.

Silicon vacancy (VSi) color centers in bulk SiC are excellent electron spin qubits. However, most spin based quantum devices require shallow spin qubits, whose dynamics is often different from that of bulk ones. Here, we demonstrate (i) a new method for creating shallow VSi (V2) spin qubits below the SiC surface by low energy ion implantation through a sacrificial SiO layer, (ii) that these shallow VSi are dipolar coupled to an electronic spin bath, analysed by Hahn echo decay, dynamical decoupling (DD), and optically pumped pulsed electron-electron double resonance experiments (OP-PELDOR), (iii) that their coherence time increases with cooling of the spin bath (from 55 μs at 297 K to 107 μs at 28 K), and that it can be further extended to 220 μs at 100 K by DD, thus demonstrating their relevance for PELDOR-based quantum sensors and processors.

From Mono- to Polynuclear Coordination Complexes with a 2,2'-Bipyrimidine-4,4'-dicarboxylate Ligand.

The coordination properties of the ligand 2,2'-bipyrimidine-4,4'-dicarboxylic acid (H) with lanthanide(III) ions (Ln = Eu, Tb, or Lu) were investigated. The syntheses of the H ligand and its salts, [K()(HO)] () and [(NH)Lu()] ( = Et, Hex, or en), are described. In the presence of LnCl salts (Ln = Lu, Eu, or Tb), the formation of [Ln()] and [Ln()(HO)] species was assessed by H nuclear magnetic resonance (NMR), spectrophotometry, and spectrofluorometric titrations in aqueous solution.

Tuning photovoltaic response in BiFeCrO films by ferroelectric poling.

Ferroelectric materials are interesting candidates for future photovoltaic applications due to their potential to overcome the fundamental limits of conventional single bandgap semiconductor-based solar cells. Although a more efficient charge separation and above bandgap photovoltages are advantageous in these materials, tailoring their photovoltaic response using ferroelectric functionalities remains puzzling. Here we address this issue by reporting a clear hysteretic character of the photovoltaic effect as a function of electric field and its dependence on the poling history.

Room Temperature Ferrimagnetism and Ferroelectricity in Strained, Thin Films of BiFeMnO.

Highly strained films of BiFeMnO (BFMO) grown at very low rates by pulsed laser deposition were demonstrated to exhibit both ferrimagnetism and ferroelectricity at room temperature and above. Magnetisation measurements demonstrated ferrimagnetism ( ∼ 600K), with a room temperature saturation moment ( ) of up to 90 emu/cc (∼ 0.58 /f.

Nanopillar spin filter tunnel junctions with manganite barriers.

The potential of a manganite ferromagnetic insulator in the field of spin-filtering has been demonstrated. For this, an ultrathin film of Sm0.75Sr0.

Electric-field control of ferromagnetism in a nanocomposite via a ZnO phase.

La2CoMnO6 (LcmO)-ZnO nanocomposite thin films grown on SrTiO3 and Nb-SrTiO3 (001) are investigated. The films grow in the form of self-assembled epitaxial vertically aligned structures. We show that, at 120 K, an electric field applied across the nanocomposite reversibly alters magnetic properties of LcmO.

Carrier density modulation by structural distortions at modified LaAlO3/SrTiO3 interfaces.

In order to study the fundamental conduction mechanism of LaAlO3/SrTiO3 (LAO/STO) interfaces, heterostructures were modified with a single unit cell interface layer of either an isovalent titanate ATiO3 (A = Ca, Sr, Sn, Ba) or a rare earth modified Sr0.5RE0.5TiO3 (RE = La, Nd, Sm, Dy) between the LAO and the STO.

Electrical and magnetic properties of La(0.35)Sr(0.65)Ti(1-x)Fe(x)O(3) thin films.

We report that the La(0.35)Sr(0.65)Ti(1-x)Fe(x)O(3) system forms a solid solution within the composition range 0≤x≤0.