3 research outputs found
El Ocaso de los dioses
De cada obra s'ha digitalitzat un programa sencer. De la resta s'han digitalitzat les parts que són diferents.Empresa: José F. ArquerOrquestra Simfònica del Gran Teatre del Liceu, director Laszlo HalaszPrograma de la temporada d'hivern 1956-1957 corresponent a la representació de El Ocaso de los Dioses, òpera d'un pròleg i tres actes amb música i llibret de Richard Wagne
Understanding Structural Incorporation of Oxygen Vacancies in Perovskite Cobaltite Films and Potential Consequences for Electrocatalysis
Owing to their excellent
mixed-ionic and electronic conductivity,
fast oxygen kinetics, and cost efficiency, layered oxygen-deficient
perovskite oxides hold great potential as highly efficient cathodes
for solid oxide fuel cells and anodes for water oxidation. Under working
conditions, cation ordering is believed to substantially enhance oxygen
diffusion while maintaining structural stability owing to the formation
of double perovskite (DP), thus attracting extensive research attention.
In contrast, the incorporation of oxygen vacancies and the associated
vacancy ordering have rarely been studied at the atomic scale, despite
their decisive roles in regulating the electronic and spin structures
as well as in differentiating the crystal structure from DP. Here,
atomic-resolution transmission electron microscopy is used to directly
image oxygen vacancies and measure their concentration in (Pr,Ba)CoO3‑δ films grown on SrTiO3 substrates.
We find that accompanied by the presence of oxygen vacancy ordering
at Co–O planes, the A–O (A = Pr/Ba) planes also exhibit
a breathing-like lattice modulation. Specifically, as confirmed by
first-principle calculations, the AO–AO interplanar spacings
are found to be linearly correlated with the vacancy concentration
in the enclosing Co–O planes. On this basis, potential consequences
of oxygen occupancy for the catalytic properties of structurally pure
PBCO phases are discussed. Through establishing a simple correlation
of oxygen concentration with the easily achievable lattice measurement,
our results pave a way for better understanding the structure–performance
relationship of oxygen-deficient complex cobaltites used for electrocatalysis
Flexible Quasi-Two-Dimensional CoFe<sub>2</sub>O<sub>4</sub> Epitaxial Thin Films for Continuous Strain Tuning of Magnetic Properties
Epitaxial
thin films of CoFe<sub>2</sub>O<sub>4</sub> (CFO) have
successfully been transferred from a SrTiO<sub>3</sub> substrate onto
a flexible polyimide substrate. By bending the flexible polyimide,
different levels of uniaxial strain are continuously introduced into
the CFO epitaxial thin films. Unlike traditional epitaxial strain
induced by substrates, the strain from bending will not suffer from
critical thickness limitation, crystalline quality variation, and
substrate clamping, and more importantly, it provides a more intrinsic
and reliable way to study strain-controlled behaviors in functional
oxide systems. It is found that both the saturation magnetization
and coercivity of the transferred films can be changed over the bending
status and show a high accord with the movement of the curvature bending
radius of the polyimide substrate. This reveals that the mechanical
strain plays a critical role in tuning the magnetic properties of
CFO thin films parallel and perpendicular to the film plane direction