A5080507734- Electronic and Structural Properties of Oxides
- Magnetic and transport properties of perovskites and related materials
- Advancements in Solid Oxide Fuel Cells
- Advanced Condensed Matter Physics
- Ferroelectric and Piezoelectric Materials
- Multiferroics and related materials
- Microwave Dielectric Ceramics Synthesis
- Catalysis and Oxidation Reactions
- Forest Insect Ecology and Management
- Block Copolymer Self-Assembly
- Forest Ecology and Biodiversity Studies
- ZnO doping and properties
- Forest ecology and management
Center for Integrated Nanotechnologies
2016-2019
Los Alamos National Laboratory
2016-2019
The University of Texas at San Antonio
2015-2019
Ulsan National Institute of Science and Technology
2015
North Carolina State University
2015
Abstract Controlling oxygen content in perovskite oxides with ABO 3 structure is one of most critical steps for tuning their functionality. Notably, there have been tremendous efforts to understand the effect changes on properties thin films that are not composed cations multiple valance states. Here, we study vacancies structural and electrical epitaxial SrFeO 3−δ (SFO), where SFO a compound states at B site. Various annealing treatments used produce different contents films, which has...
Epitaxial SrFeO3−δ (SFO) thin films have been grown on various substrates by pulsed laser deposition. The structural and electrical properties of SFO are monitored with time in different atmospheres at room temperature, showing time-dependent crystal structure conductivity. increased out-of-plane lattice parameter resistivity over associated the oxygen vacancies density films. epitaxial strain plays an important role determining initial resistivity, sample environment determines trend change...
A variety of emergent phenomena have been enabled by interface engineering in complex oxides. The existence an intrinsic interfacial layer has often found at oxide heterointerfaces. However, the role such interlayerin controlling functionalities is not fully explored. Here, we report control exchange bias (EB) single-phase manganite thin films with nominallyuniform chemical composition across interfaces. sign EB depends on magnitude cooling field. pinned layer, confirmed polarized neutron...
The Sr and Fe codoped double perovskites PrBaCo2O5.5+δ (PrBCO) thin films of Pr(Ba0.5Sr0.5)(Co1.5Fe0.5)O5.5+δ (PBSCFO) were epitaxially grown for chemical catalytic studies. resistance behavior PBSCFO epitaxial was monitored under the switching flow reducing oxidizing gases as a function gas time, t, using an electrical conductivity relaxation (ECR) experimental setup. R(t) vs t relationships determined at various temperatures show occurrence two oxidation processes, Co2+/Co3+ ↔ Co3+...
Oxygen content in transition metal oxides is one of the most important parameters to control for desired physical properties. Recently, we have systematically studied oxygen and property relationship double perovskite PrBaCo2O5.5+δ (PBCO) thin films deposited on LaAlO3 substrates. The was varied by in-situ annealing a nitrogen, oxygen, or ozone environment. Associated with content, out-of-plane lattice parameter progressively decreases increasing films. saturated magnetization shows drastic...
Abstract The ability to control nanoparticle size, concentration, and distribution in epitaxial nanocomposite films has been a formidable challenge the synthesis of nanostructured composite materials. Here, novel 3D super‐nanocomposite (3D‐sNC) architecture is successfully demonstrated by integrating superlattice vertically aligned structures. In 3D‐sNC architecture, feature size nanocylinders such as height/lateral dimension vertical/lateral spacing can be precisely controlled....
Epitaxial PrBaCo2O5+δ (PBCO, 0≤ δ ≤ 1) thin films were deposited by pulsed laser deposition. The structural and electrical properties of the characterized at high temperatures in reduced environments. X-ray diffraction scans temperature environment show potential transitions PBCO as evidenced both a large (Δl = 0.335 nm) expansion out-plane (c-axis) lattice, due to thermal chemical expansion, step c-axis lattice parameter. These indicate presence oxygen vacancy ordering content is reduced....
A symmetric PBCO/YSZ/PBCO cell (where PBCO refers to PrBaCo<sub>2</sub>O<sub>5.5+δ</sub>, and YSZ yttria stabilized zirconia) was designed fabricated for the investigation of catalytic nature reaction kinetics CO<sub>2</sub> on surfaces.
The role of temperature and the oxygen content in structural transformation electrical conductivity epitaxial double perovskite LaBaCo2O5+δ (0≤ δ ≤ 1) thin films was systematically investigated. Reciprocal space mapping ω-2θ x-ray diffraction performed at different temperatures vacuum indicate that vacancies become ordered high a reducing environment. changes degree vacancy ordering result strong in-plane anisotropic lattice deformation large thermal expansion coefficient along c-axis...
The piezo response is greatly strengthened by the interface effect and twining structures in Ba(Zr,Ti)O<sub>3</sub>/(Ba,Ca)TiO<sub>3</sub>multilayered heterostructures.