Scientific Highlights
Structure and Conductivity of Epitaxial Thin Films of In-Doped BaZrO3‑Based Proton Conductors
Epitaxial thin films of the proton-conducting perovskite BaZr0.53In0.47O3−δH0.47−2δ, grown by pulsed laser deposition, were investigated in their hydrated and dehydrated conditions through a multitechnique approach with the aim to study the structure and proton concentration depth profile and their relationship to proton conductivity.
Investigating the Role of Strain toward the Oxygen Reduction Activity on Model Thin Film Pt Catalysts
Environmentally friendly energy conversion devices such as fuel cells are becoming more and more attractive. However, major impediments to large-scale application still arise on the material side, related to the cost and poor performance of the cathode catalyst. State-of-the-art electrocatalysts are all Pt-based materials, suffering from poor electrochemical oxygen reduction kinetics.
Coexisting multiple order parameters in single-layer LuMnO3 films
Magnetoelectric multiferroics hold great promise for electrical control of magnetism or magnetic control of ferroelectricity. However, single phase ferroelectric materials with a sizeable ferromagnetic magnetization are rare. Here, we demonstrate that a single-phase orthorhombic LuMnO3 thin film features coexisting magnetic and ferroelectric orders.
In situ stress observation in oxide films and how tensile stress influences oxygen ion conduction
Many properties of materials can be changed by varying the interatomic distances in the crystal lattice by applying stress. Ideal model systems for investigations are heteroepitaxial thin films where lattice distortions can be induced by the crystallographic mismatch with the substrate. Here we describe an in situ simultaneous diagnostic of growth mode and stress during pulsed laser deposition of oxide thin films.
The flip-over effect in pulsed laser deposition: Is it relevant at high background gas pressures?
In pulsed laser deposition the use of a rectangular or elliptical beam spot with a non 1:1 aspect ratio leads to the so called flip-over effect. Here, the longest dimension of the laser spot results in the shortest direction of plasma plume expansion.
Interplay between magnetic order at Mn and Tm sites alongside the structural distortion in multiferroic films of o-TmMnO3
We employ resonant soft x-ray diffraction to individually study the magnetic ordering of the Mn and the Tm sublattices in single-crystalline films of orthorhombic (o−)TmMnO3. The same magnetic ordering wave vector of (0q0) with q≈0.46 is found for both ionic species, suggesting that the familiar antiferromagnetic order of the Mn ions induces a magnetic order on the Tm unpaired 4f electrons.
Crystallization of zirconia based thin films
In pulsed laser deposition the use of a rectangular or elliptical beam spot with a non 1:1 aspect ratio leads to the so called flip-over effect. Here, the longest dimension of the laser spot results in the shortest direction of plasma plume expansion.
Multiferroic Properties of o−LuMnO3 Controlled by b-Axis Strain
Strain is a leading candidate for controlling magnetoelectric coupling in multiferroics. Here, we use x-ray diffraction to study the coupling between magnetic order and structural distortion in epitaxial films of the orthorhombic (o-) perovskite LuMnO3. An antiferromagnetic spin canting in the E-type magnetic structure is shown to be related to the ferroelectrically induced structural distortion and to a change in the magnetic propagation vector.
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.