Articles in 2020

To enhance supercurrent of iron-chalcogenide (FST) superconductor thin films, we induced nanostrain in FST thin films. The nanostrain was generated around nanoscale defects which were formed by the inserted a trace amount of oxide artificially inside FST matrix during the growth of FST thin film using sequential pulsed laser deposition. In particular, the critical current density (J_c) of the nanostrained FST thin films was significantly improved without dominant degradation of critical transition temperature.

Hybrid films with WO₃·H₂O nanoparticles-embedded chitosan on amorphous WO₃ films are newly designed for multi-functional devices with electrochromic energy storage performances.

The authors demonstrate that the inverse spin Hall effect (ISHE) and pure spin current relaxation in Ni₈₀Fe₂₀ (Py) are strong magnetization orientation dependent through longitudinal spin-Seebeck effect measurement in YIG/Cu/Py/Ir₂₅Mn₇₅ spin valve heterostructure. With the relative orientation of the magnetization of YIG and Py varying from perpendicular (⊥) to collinear (||), it has been found that the detected ISHE amplitude in 10 nm Py increases by 80%. Besides, the spin-diffusion length λ_sf varies from \(\lambda _{{\mathrm{sf}}}^ \bot\) = 1.0 ± 0.1 nm to \(\lambda _{{\mathrm{sf}}}^\parallel\) = 2.8 ± 0.5 nm and the effective spin Hall angle \(\theta _{{\mathrm{SH}}}^{{\mathrm{eff}}}\left( \bot \right)/\theta _{{\mathrm{SH}}}^{{\mathrm{eff}}}\left( \parallel \right) = 1.5\).

New self-healing zwitterionic polymer networks are prepared and the healing efficiency is quantified by 3D plotting, as well as volume calculation of the damaged surface after tactile profile scans. The results are complemented by comprehensive investigations of the mechanical, viscoelastic, and thermal properties in order to identify structure-property relationships.

Topologically electronic state receives great attention during the past decades, owing to their topologically protected metallic edge states. Topological phase transition between nontrivial and trivial states is thus intriguing for not only information storage but also for dissipationless information transport, which is usually driven by pressure or gate voltage. Triggering topological phase transition without physical contact fascinates the scientific community. Due to contrast band topology, the trivial and nontrivial topological materials possess different optical responses. Based on this, a novel non-contacting optical illumination scheme is predicted by first-principles calculations to drive topological phase transition in IV–VI semiconductors.

An electret can be created in a complex transition metal oxide LaMnO₃ by tip-induced electric fields with a considerable surface height change via solid-state electrochemical amorphization. The surface charge density of the formed electret area reaches ~400 nC cm⁻² and persists without significant charge reduction for more than a year. Our finding opens a new horizon for multifunctional transition metal oxides by providing an electric counterpart to permanent magnets.