Scientific Highlights
4-spin plaquette singlet state in the Shastry–Sutherland compound SrCu2(BO3)2
The study of interacting spin systems is of fundamental importance for modern condensed-matter physics. On frustrated lattices, magnetic exchange interactions cannot be simultaneously satisfied, and often give rise to competing exotic ground states. The frustrated two-dimensional Shastry–Sutherland lattice realized by SrCu2(BO3)2 is an important test to our understanding of quantum magnetism.
Determination of Conduction and Valence Band Electronic Structure of LaTiOxNy Thin Films
The nitrogen substitution into the oxygen sites of several oxide materials leads to a reduction of the band gap to the visible-light energy range, which makes these oxynitride semiconductors potential photocatalysts for efficient solar water splitting. Oxynitrides typically show a different crystal structure compared to the pristine oxide material.
LaTiOxNy thin film model systems for photocatalytic water splitting: physicochemical evolution of the solid-liquid interface and the role of the crystallographic orientation
The size of the band gap and the energy position of the band edges make several oxynitride semiconductors promising candidates for efficient hydrogen and oxygen production under solar light illumination. The intense research efforts dedicated to oxynitride materials have unveiled the majority of their most important properties. However, two crucial aspects have received much less attention.
Tuning the multiferroic mechanisms of TbMnO3 by epitaxial strain
A current challenge in the field of magnetoelectric multiferroics is to identify systems that allow a controlled tuning of states displaying distinct magnetoelectric responses. Here we show that the multiferroic ground state of the archetypal multiferroic TbMnO3 is dramatically modified by epitaxial strain. Neutron diffraction reveals that in highly strained films the magnetic order changes from the bulk-like incommensurate bc-cycloidal structure to commensurate magnetic order.
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.
Nanoparticle-Based Magnetoelectric BaTiO3–CoFe2O4 Thin Film Heterostructures for Voltage Control of Magnetism
Multiferroic composite materials combining ferroelectric and ferromagnetic order at room temperature have great potential for emerging applications such as four-state memories, magnetoelectric sensors, and microwave devices.
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.
High-resolution hard x-ray magnetic imaging with dichroic ptychography
Imaging the magnetic structure of a material is essential to understanding the influence of the physical and chemical microstructure on its magnetic properties. Magnetic imaging techniques, however, have been unable to probe three-dimensional micrometer-size systems with nanoscale resolution. Here we present the imaging of the magnetic domain configuration of a micrometer-thick FeGd multilayer with hard x-ray dichroic ptychography at energies spanning both the Gd L3 edge and the Fe K edge, providing a high spatial resolution spectroscopic analysis of the complex x-ray magnetic circular dichroism.