scholarly journals Carrier localization in perovskite nickelates from oxygen vacancies

2019 ◽  
Vol 116 (44) ◽  
pp. 21992-21997 ◽  
Author(s):  
Michele Kotiuga ◽  
Zhen Zhang ◽  
Jiarui Li ◽  
Fanny Rodolakis ◽  
Hua Zhou ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Rare Earth ◽  
Oxygen Vacancies ◽  
Switching Behavior ◽  
Carrier Localization ◽  
Unusual Behavior ◽  
Oxide Semiconductors ◽  
Oxide Heterostructures ◽  
Correlated Electron ◽  
Analog Resistance

Point defects, such as oxygen vacancies, control the physical properties of complex oxides, relevant in active areas of research from superconductivity to resistive memory to catalysis. In most oxide semiconductors, electrons that are associated with oxygen vacancies occupy the conduction band, leading to an increase in the electrical conductivity. Here we demonstrate, in contrast, that in the correlated-electron perovskite rare-earth nickelates, RNiO3 (R is a rare-earth element such as Sm or Nd), electrons associated with oxygen vacancies strongly localize, leading to a dramatic decrease in the electrical conductivity by several orders of magnitude. This unusual behavior is found to stem from the combination of crystal field splitting and filling-controlled Mott–Hubbard electron–electron correlations in the Ni 3d orbitals. Furthermore, we show the distribution of oxygen vacancies in NdNiO3 can be controlled via an electric field, leading to analog resistance switching behavior. This study demonstrates the potential of nickelates as testbeds to better understand emergent physics in oxide heterostructures as well as candidate systems in the emerging fields of artificial intelligence.

Effects of rare earth metal doping on Au/ReZrO2 catalysts for efficient hydrogen generation from formic acid

2021 ◽  
Vol 45 (12) ◽  
pp. 5704-5711
Author(s):  
Luming Wu ◽  
Yu Hao ◽  
Shaohua Chen ◽  
Rui Chen ◽  
Pingchuan Sun ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Rare Earth ◽  
Rare Earth Metal ◽  
Oxygen Vacancies ◽  
Hydrogen Generation ◽  
Earth Metal ◽  
Support Interaction ◽  
Metal Support Interaction ◽  
Metal Support ◽  
Metal Doped

Rare earth metal doped ZrO2 can promote the formation of oxygen vacancies in zirconia, which enhances the metal–support interaction, finally promoting catalytic activity of FA dehydrogenation.

Heterojunction-induced nickel-based oxygen vacancies on N-enriched porous carbons for enhanced alkaline hydrogen oxidation and oxygen reduction

2021 ◽  
Author(s):  
Jin-Tao Ren ◽  
Zhong-Yong Yuan
Keyword(s):  
Nickel Oxide ◽  
Oxygen Reduction ◽  
Oxygen Vacancies ◽  
Hydrogen Oxidation ◽  
Graphitic Carbon ◽  
Porous Carbons ◽  
Oxide Heterostructures ◽  
Alkaline Water ◽  
Oxygen Reduction Reactions

In situ-formed nickel/nickel oxide heterostructures coupled with N-doped graphitic carbon significantly promote the hydrogen oxidation and oxygen reduction reactions in alkaline water.

scholarly journals Solid solubility of rare earth elements (Nd, Eu, Tb) in In2−xSnxO3 – effect on electrical conductivity and optical properties

2014 ◽  
Vol 43 (25) ◽  
pp. 9620-9632 ◽  
Author(s):  
T. O. L. Sunde ◽  
M. Lindgren ◽  
T. O. Mason ◽  
M.-A. Einarsrud ◽  
T. Grande
Keyword(s):  
Electrical Conductivity ◽  
Optical Properties ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Band Gap ◽  
Solid Solubility ◽  
Wide Band ◽  
Wide Band Gap ◽  
Recent Interest ◽  
Wide Band Gap Semiconductors

Wide band-gap semiconductors doped with luminescent rare earth elements (REEs) have attracted recent interest due to their unique optical properties.

MECHANISM STUDY ON OXYGEN VACANCY INDUCED RESISTANCE SWITCHING IN Au/LaMnO3/SrNb0.01Ti0.99O3

2013 ◽  
Vol 27 (11) ◽  
pp. 1350074 ◽  
Author(s):  
YU-LING JIN ◽  
ZHONG-TANG XU ◽  
KUI-JUAN JIN ◽  
CHEN GE ◽  
HUI-BIN LU ◽  
...  
Keyword(s):  
Oxygen Vacancy ◽  
Oxygen Vacancies ◽  
Vacancy Concentration ◽  
Resistance Switching ◽  
Switching Behavior ◽  
Oxygen Vacancy Concentration ◽  
Mechanism Study ◽  
Switching Performance ◽  
Switching Characteristics

Mechanism of resistance switching in heterostructure Au / LaMnO 3/ SrNb 0.01 Ti 0.99 O 3 was investigated. In Au / LaMnO 3/ SrNb 0.01 Ti 0.99 O 3 devices the LaMnO 3 films were fabricated under various oxygen pressures. The content of the oxygen vacancies has a significant impact on the resistance switching performance. We propose that the resistance switching characteristics of Au / LaMnO 3/ SrNb 0.01 Ti 0.99 O 3 arise from the modulation of the Au / LaMnO 3 Schottky barrier due to the change of the oxygen vacancy concentration at Au / LaMnO 3 interface under the external electric field. The effect of the oxygen vacancy concentration on the resistance switching is explained based on the self-consistent calculation. Both the experimental and numerical results confirm the important role of the oxygen vacancies in the resistance switching behavior.

scholarly journals Antisite-disorder engineering in La-based oxide heterostructures via oxygen vacancy control

2018 ◽  
Vol 20 (26) ◽  
pp. 17871-17880 ◽  
Author(s):  
Urmimala Dey ◽  
Swastika Chatterjee ◽  
A. Taraphder
Keyword(s):  
Oxygen Vacancy ◽  
Transport Properties ◽  
Oxygen Vacancies ◽  
Major Effect ◽  
Oxide Heterostructures ◽  
Key Players ◽  
Antisite Defects ◽  
Antisite Disorder

It has been realized lately that disorder, primarily in the form of oxygen vacancies, cation stoichiometry, atomic inter-diffusion and antisite defects, has a major effect on the electronic and transport properties of a 2D electron liquid at oxide hetero-interfaces – the first and the last being the two key players.

scholarly journals Surface Oxygen Vacancies: Dynamics of Photo‐Induced Surface Oxygen Vacancies in Metal‐Oxide Semiconductors Studied Under Ambient Conditions (Adv. Sci. 22/2019)

2019 ◽  
Vol 6 (22) ◽  
pp. 1970132 ◽  
Author(s):  
Daniel Glass ◽  
Emiliano Cortés ◽  
Sultan Ben‐Jaber ◽  
Thomas Brick ◽  
William J. Peveler ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Oxygen Vacancies ◽  
Metal Oxide Semiconductors ◽  
Surface Oxygen ◽  
Ambient Conditions ◽  
Oxide Semiconductors

scholarly journals Resistive switching behavior in α-In2Se3 nanoflakes modulated by ferroelectric polarization and interface defects

RSC Advances ◽  
2019 ◽  
Vol 9 (52) ◽  
pp. 30565-30569 ◽  
Author(s):  
Pengfei Hou ◽  
Siwei Xing ◽  
Xin Liu ◽  
Cheng Chen ◽  
Xiangli Zhong ◽  
...  
Keyword(s):  
Resistive Switching ◽  
Oxygen Vacancies ◽  
Switching Behavior ◽  
Ferroelectric Polarization ◽  
Resistive Switching Behavior ◽  
Free Carriers ◽  
Interface Defects ◽  
Out Of Plane ◽  
Planar Device

A planar device based on an α-In2Se3 nanoflake, in which the in-plane/out-of-plane polarization, free carriers and oxygen vacancies in SiO2 contribute to the resistive switching behavior of the device.

scholarly journals Raman Study of Nanocrystalline-Doped Ceria Oxide Thin Films

Coatings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 432 ◽  
Author(s):  
Nursultan Kainbayev ◽  
Mantas Sriubas ◽  
Darius Virbukas ◽  
Zivile Rutkuniene ◽  
Kristina Bockute ◽  
...  
Keyword(s):  
Thin Films ◽  
Rare Earth ◽  
Cerium Oxide ◽  
Oxygen Vacancies ◽  
Raman Shift ◽  
Size Factor ◽  
Doped Ceria ◽  
X Ray ◽  
Sio2 Substrate ◽  
Lower Frequencies

Samarium-doped ceria (SDC) and gadolinium-doped ceria (GDC) thin films were formed by e-beam vapor deposition on SiO2 substrate, changing the deposition rate and substrate temperature during the deposition. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-Ray spectrometry (EDS) were employed in order to investigate the structure ad morphology of the films. A single Raman peak describing the structure of undoped CeO2 was observed at a frequency of 466 cm−1. Doping of cerium oxide with rare-earth elements shifted the peak to lower frequencies (for Sm—462 cm−1). This shift occurs due to the increased number of oxygen vacancies in doped cerium oxide and it depends on the size and concentration factor of the dopant. It was found that wavenumbers and their intensity differed for the investigated samples, even though the peaks resembled each other in shape. The indicated bands for doped ceria originated as a result of the Raman regime (F2g) of fluorite dioxide associated with the space group (Fm3m). The observed peak‘s position shifting to a lower frequency range demonstrates the symmetric vibrations of oxygen ions around Ce4+ ions in octahedra CeO8. Raman shift to the lower frequencies for the doped samples has two reasons: an increase in oxygen vacancies caused by doping cerium oxide with rare-earth materials and the size factor, i.e., the change in frequency Δω associated with the change in the lattice constant Δa.

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