Effect of Lattice Strain on the Formation of Ruddlesden-Popper Faults in Heteroepitaxial LaNiO for Oxygen Evolution Electrocatalysis.

A great deal of research has recently been focused on Ruddlesden-Popper (RP) two-dimensional planar faults consisting of intervened [AO] monolayers in an ABO perovskite framework due to the structurally peculiar shear configuration. In this work, we scrutinize the effect of elastic strain on the generation behavior of RP faults, which are electrocatalytically very active sites for the oxygen evolution reaction (OER), in (001) epitaxial LaNiO thin films through by using two distinct single-crystal substrates with different cubic lattice parameters. Atomic-scale direct observations reveal that RP faults can be more favorably created when tensile misfit strain is exerted.

All-Solid-State Synaptic Transistors with High-Temperature Stability Using Proton Pump Gating of Strongly Correlated Materials.

Designing energy-efficient artificial synapses with adaptive and programmable electronic signals is essential to effectively mimic synaptic functions for brain-inspired computing systems. Here, we report all-solid-state three-terminal artificial synapses that exploit proton-doped metal-insulator transition in a correlated oxide NdNiO (NNO) channel by proton (H) injection/extraction in response to gate voltage. Gate voltage reversibly controls the H concentration in the NNO channel with facile H transport from a H-containing porous silica electrolyte.

Influence of tensile-strain-induced oxygen deficiency on metal-insulator transitions in NdNiO epitaxial thin films.

We report direct evidence that oxygen vacancies affect the structural and electrical parameters in tensile-strained NdNiO epitaxial thin films by elaborately adjusting the amount of oxygen deficiency (δ) with changing growth temperature T . The modulation in tensile strain and T tended to increase oxygen deficiency (δ) in NdNiO thin films; this process relieves tensile strain of the thin film by oxygen vacancy incorporation. The oxygen deficiency is directly correlated with unit-cell volume and the metal-insulator transition temperature (T ), i.

Facile Phase Control of Multivalent Vanadium Oxide Thin Films (VO and VO) by Atomic Layer Deposition and Postdeposition Annealing.

Atomic layer deposition was adopted to deposit VO thin films using vanadyl tri-isopropoxide {VO[O(CH)], VTIP} and water (HO) at 135 °C. The self-limiting and purge-time-dependent growth behaviors were studied by ex situ ellipsometry to determine the saturated growth conditions for atomic-layer-deposited VO. The as-deposited films were found to be amorphous.

Modulation of metal-insulator transitions by field-controlled strain in NdNiO3/SrTiO3/PMN-PT (001) heterostructures.

The band width control through external stress has been demonstrated as a useful knob to modulate metal-insulator transition (MIT) in RNiO3 as a prototype correlated materials. In particular, lattice mismatch strain using different substrates have been widely utilized to investigate the effect of strain on transition temperature so far but the results were inconsistent in the previous literatures. Here, we demonstrate dynamic modulation of MIT based on electric field-controlled pure strain in high-quality NdNiO3 (NNO) thin films utilizing converse-piezoelectric effect of (001)-cut Pb(Mg(1/3)Nb(2/3)O3-(PbTiO3) (PMN-PT) single crystal substrates.