相关论文: A physical method for investigating defect chemist…
Using density-functional theory (DFT) we calculate the Gibbs free energy to determine the lowest-energy structure of a RuO_2(110) surface in thermodynamic equilibrium with an oxygen-rich environment. The traditionally assumed stoichiometric…
Oxygen-defect control has long been considered an influential tuning knob for producing various property responses in complex oxide films. In addition to physical property changes, modification to the lattice structure, specifically lattice…
We present an approach to tune the effective mass in an oxide semiconductor by a double doping mechanism. We demonstrate this in a model oxide system Sr$_{1-x}$La$_x$TiO$_{3-\delta}$, where we can tune the effective mass ranging from…
Controlling and measuring the concentration of para-D2 is an essential step toward realizing solid deuterium as an intense ultra-cold neutron (UCN) source. To this end, we implemented an experimental technique to convert para- to…
The lack of a mechanistic framework for chemical reactions forming inorganic extended solids presents a challenge to accelerated materials discovery. We demonstrate here a combined computational and experimental methodology to tackle this…
We have designed and developed a new experimental setup, based on the 3-omega method, to measure thermal conductivity, heat capacity and electrical resistivity of a variety of samples in a broad temperature range (2-550 K) and under…
This study discovers a reversible order-disorder transition (ODT) in a 10-cation compositionally complex ceramic, (Nd0.15Pr0.15Dy0.8Ho0.8Er0.8Ti0.2Yb0.1Hf0.1Zr0.1Nb0.8)O7-delta, induced via annealing in oxidized vs. reduced environments at…
Thin films of Co-TiO2 are deposited on silicon and quartz substrates using Pulse Laser Deposition (PLD) process at various oxygen partial pressures ranging from 6.6 x 10-3 Pascals (Pa) to 53 Pa. Crystal structure, transport and magnetic…
Chemical looping methane partial oxidation provides an energy and cost effective route for methane utilization. However, there is considerable CO2 co-production in state-of-the-art chemical looping systems, rendering a decreased…
We report the first experimental evidence for a metallic phase in fluid molecular oxygen. Our electrical conductivity measurements of fluid oxygen under dynamic quasi-isentropic compression show that a non-metal/metal transition occurs at…
The possible redox (oxidation reduction) chemical methods for precisely determining the oxygen content in the perovskite manganites including hole-doped La1-xCaxMnOy and electron-doped La1-xTexMnOy compounds are described. For manganites…
Understanding oxidation mechanisms of layered semiconducting transition-metal dichalcogenide (TMDC) is important not only for controlling native oxide formation but also for synthesis of oxide and oxysulfide products. Here, reactive…
We provide insights into the influence of surface termination on the oxygen vacancy incorporation for the perovskite model material SrTiO3 during annealing in reducing gas environments. We present a novel approach to control to tailor the…
Superconductivity (Tc), like any other property of a condensate, depends critically on the concentration of atoms. "Physical" dilution of metals exists in nonstoichiometric compounds. In such stoichiometric compounds as oxides, oxygen…
The superconducting properties of high-\tc\ materials are functions of carriers concentration, which is controlled by the concentration of defects including heterovalent cations, interstitial oxygen ions, and oxygen vacancies. Here we…
The analysis of the electronic surface properties of transition metal oxides being key materials for future nanoelectronics requires a direct characterization of the conductivity with highest spatial resolution. Using local conductivity…
In recent years due to improvements in calculation methods and increased computer power, it has become possible to perform first-principles investigations for ``simple'' chemical reactions at surfaces. We have carried out such studies for…
Solid state ionic approaches for modifying ion distributions in getter/oxide heterostructures offer exciting potentials to control material properties. Here we report a simple, scalable approach allowing for total control of the…
Some oxygen defective metal oxides, such as cerium and bismuth oxides, have recently shown exceptional electrostrictive properties that are even superior to the best performing lead-based electrostrictors, e.g. lead-magnesium-niobates…
Understanding the oxidation and reduction mechanisms of catalytically active transition metal nanoparticles is important to improve their application in a variety of chemical processes. In nanocatalysis the nanoparticles can undergo…