A5016167144- Physics of Superconductivity and Magnetism
- Magnetic and transport properties of perovskites and related materials
- Advanced Condensed Matter Physics
- Iron-based superconductors research
- Magnetic properties of thin films
- Rare-earth and actinide compounds
- Quantum and electron transport phenomena
- Microstructure and Mechanical Properties of Steels
- Magnetic Bearings and Levitation Dynamics
- Advanced Materials Characterization Techniques
- Topological Materials and Phenomena
- Solidification and crystal growth phenomena
- Semiconductor Quantum Structures and Devices
- Nuclear Physics and Applications
- Magnetic Properties and Applications
- Laser Design and Applications
- Semiconductor materials and devices
- Superconducting Materials and Applications
National University of Singapore
2021-2025
Block Engineering (United States)
2021
University of Houston
1992
University of Louisiana at Monroe
1970
We report the observation of superconductivity in infinite-layer Ca-doped LaNiO 2 (La 1− x Ca NiO ) thin films and construct their phase diagram. Unlike metal-insulator transition Nd- Pr-based nickelates, undoped underdoped La are entirely insulating from 300 K down to K. A superconducting dome is observed at 0.15 < 0.3 with weakly behavior overdoped regime. Moreover, sign Hall coefficient R H changes low temperature for samples a higher doping level. However, distinct -sign-change...
Superconductivity in infinite-layer nickelates holds exciting analogies with that of cuprates, similar structures and 3d-electron count. Using resonant inelastic x-ray scattering, we studied electronic magnetic excitations charge density correlations Nd_{1-x}Sr_{x}NiO_{2} thin films without an SrTiO_{3} capping layer. We observe dispersing magnons only the capped samples, progressively dampened at higher doping. detect elastic scattering peak uncapped x=0 compound wave vector (∼⅓,0),...
Nickel-based complex oxides have served as a playground for decades in the quest copper-oxide analog of high-temperature superconductivity. They may provide clues towards understanding mechanism and an alternative route superconductors. The recent discovery superconductivity infinite-layer nickelate thin films has fulfilled this pursuit. However, material synthesis remains challenging, direct demonstration perfect diamagnetism is still missing, role interface bulk to superconducting...
Topotactic reduction utilizing metal hydrides as reagents has emerged an effective approach to achieve exceptionally low oxidization states of ions and unconventional coordination networks. This method opens avenues the development entirely new functional materials, with one notable example being infinite-layer nickelate superconductors. However, effect on atomic reconstruction electronic structures-crucial for superconductivity-remains largely unresolved. We designed two sets control...
After the reward of more than two decades pursuit on high-Tc cuprate analog with hope to obtain a better understanding mechanism superconductivity, discovery superconductivity in infinite-layer nickelate brings mystery picture expected. Tops list questions are perhaps (1) absence bulk and limited thickness phase thin film, (2) La-nickelate despite it being earliest studied rare-earth nickelate, role 4f orbital recipe (3) Meissner effect suspect origin from interface, (4) whether hosts...
Abstract A key open question in the study of layered superconducting nickelate films is role that hydrogen incorporation into lattice plays appearance state. Due to challenges stabilizing highly crystalline square planar films, are prepared by deposition a more stable parent compound which then transformed target phase via topotactic reaction with strongly reducing agent such as CaH 2 . Recent studies, both experimental and theoretical, have introduced possibility from may be critical for...
Lifting capacities greater than 41 N/cm2 (60 psi) at 77 K have been achieved using a combination of permanent magnets and high quality melt-textured YBa2Cu3O7−δ (YBCO). The key concept this hybrid superconducting magnetic bearing (HSMB) is the use strong repulsion attraction from to support loads in conjunction with flux pinning type II superconductor counteract instabilities system consisting only. To illustrate concept, radial axial forces between magnet/superconductor, magnet/magnet,...
Abstract Unconventional high‐temperature superconductivity has long been a captivating puzzle in condensed matter physics. The 1987 Nobel Prize Physics celebrated the discovery of copper oxide ceramics. Nearly four decades later, broad class superconducting oxides yet to be demonstrated, and fundamental understanding pairing mechanism remains inconclusive. Recently, nickel have emerged as new superconductors, beyond copper, where correlated phases can controlled by doping, pressure, strain,...
The etch reaction has been studied as a function of flow rate, temperature, and surface area. Experimental calculated equilibrium constants for the have compared. formation is considered. variation sample texture with gas composition examined.
Abstract Nickel-based complex oxides have served as a playground for decades in the quest copper-oxide analog of high-temperature (high- T c ) superconductivity. They may provide key points towards understanding mechanism and an alternative route high- superconductors. The recent discovery superconductivity infinite-layer nickelate thin films has fulfilled this pursuit. Thus far, however, material synthesis remains challenging. demonstration perfect diamagnetism is still missing, role...
The interplay between dimensionality and various phases of matter is a central inquiry in condensed physics. New are often discovered through spontaneously broken symmetry. Understanding the superconductivity high-temperature cuprate analogue $-$ layered nickelates revealing new symmetry-breaking state keys to deciphering underlying pairing mechanism. Here, we demonstrate highly-tunable rotational symmetry square-planar nickelates. superconducting state, probed by critical current...
A key open question in the study of layered superconducting nickelate films is role that hydrogen incorporation into lattice plays appearance state. Due to challenges stabilizing highly crystalline square planar films, are prepared by deposition a more stable parent compound which then transformed target phase via topotactic reaction with strongly reducing agent such as CaH$_2$. Recent studies, both experimental and theoretical, have introduced possibility from may be critical for...
Topotactic reduction utilizing metal hydrides as reagents emerges an effective approach to achieve exceptionally low oxidization states of ions and unconventional coordination networks. This method opens avenues the development entirely new functional materials, with one notable example being infinite-layer nickelate superconductors. However, effect on atomic reconstruction electronic structures -- crucial for superconductivity remains largely unresolved. We design two sets control...
Abstract Among the vast magnetic heterostructures explored in Condensed Matter Physics, two contrasting interpretations of hump‐shaped Hall Effects remain ambiguous and debated, namely, overlap opposite‐signed Karplus–Luttinger loops associated with inhomogeneous collinear domains perpendicular anisotropy, or Geometrical/Topological Effect emanated from hexagonal close‐packed lattice Skyrmion ground state smoothly varying non‐collinear moments. Their similarity topology implies difficulty...
Among various magnetic thin film heterostructures in solid state Physics, two contrasting mechanisms of the hump-shaped Hall Effects remain ambiguous and debated, namely overlap opposite-signed Karplus-Luttinger Hall-loops associated with inhomogeneous collinear bubbles perpendicular anisotropy, or Topological/geometrical Effect skyrmions. Their similarity topology imposes difficulty discrimination via imaging. Here, this ambiguity is overcome by divergence exponent angle-dependent hump peak...