A5016938506- Ferroelectric and Piezoelectric Materials
- Thermal properties of materials
- Magnetic and transport properties of perovskites and related materials
- Conducting polymers and applications
- Electronic and Structural Properties of Oxides
- Multiferroics and related materials
- Advanced Condensed Matter Physics
- Composite Material Mechanics
- Acoustic Wave Resonator Technologies
- Electrochemical Analysis and Applications
- Crystal Structures and Properties
- Pigment Synthesis and Properties
- Manufacturing Process and Optimization
- Corrosion Behavior and Inhibition
- Perovskite Materials and Applications
- Luminescence Properties of Advanced Materials
- Polymer Synthesis and Characterization
- Silicone and Siloxane Chemistry
- Electrocatalysts for Energy Conversion
- Porphyrin and Phthalocyanine Chemistry
- Dielectric materials and actuators
- X-ray Diffraction in Crystallography
- Advanced materials and composites
- Luminescence and Fluorescent Materials
- Digital Transformation in Industry
Cornell University
2010-2021
Harvard University
2010
Stanford University
2009
Abstract In this paper, the pore filling of spiro‐OMeTAD (2,2′,7,7′‐tetrakis‐( N , ‐di‐ p ‐methoxyphenylamine)9,9′‐spirobifluorene) in mesoporous TiO 2 films is quantified for first time using XPS depth profiling and UV–Vis absorption spectroscopy. It shown that can penetrate entire film, its concentration constant throughout film. We determine a 2.5‐µm‐thick volume pores 60–65% filled. The become less filled when thicker are used. Such fraction much higher than solution because excess on...
CsPbF3 is the only experimentally synthesized ABF3 fluoride perovskite with a polar ground state. We use as guide in our search for rules to rationally design new ABX3 fluorides and halides from first-principles model compound study interactions of lone pairs, octahedral rotations, A- B-site driven ferroelectricity. find that pair cation on serves stabilize state, analogous role cations A-site oxide perovskites. However, we also determines pattern nonpolar structural distortions, rotations...
Epitaxial perovskite oxide thin films and heterostructures are a highly active materials research topic generating both fundamental applied interest. This manuscript reports the roles of oxidation kinetics film deposition rate on growth phase-pure complex oxides by molecular-beam epitaxy, one premier techniques for these materials, in regime that is traditionally described as being governed thermodynamics. It found surface surprisingly important PbTiO${}_{3}$ formulating simple kinetic...
We study the interplay between epitaxial strain, film thickness, and electric field in creation, modification, design of distinct ferroelastic structures PbTiO3 thin films. Strain thickness greatly affect formed, providing a two-variable parameterization resulting self-assembly. Under applied fields, these strain-engineered are highly malleable, especially when a/c a1/a2 superdomains coexist. To reconfigure achieve self-assembled nanoscale-ordered morphologies, pure ferroelectric switching...
Eighteen Pt-M binary (M = Sn, Ta, W, Mo, Ru, Fe, In, Pd, Hf, Zn, Zr, Nb, Sc, Ni, Ti, V, Cr, Rh) thin film composition spreads were deposited at low M concentrations using magnetron sputtering and screened for methanol ethanol electrooxidation activity a fluorescence assay. Characterization of these films was performed high energy X-ray diffraction fluorescence. The electrochemical assay revealed highest in the with Ru. In) showed below 5 atom-% fraction Pt fcc(111) texturing Pt-Fe showing...
In numerous symmetric θ-2θ scans of phase-pure epitaxial complex oxide thin films grown on single-crystal substrates, we observe x-ray diffraction peaks that correspond to neither the film nor substrate crystal structure. These are result multiple, sequential events occur from both and substrate. The occurrence so-called “hybrid” reflections, while described in literature, is not widely reported within thin-film community. We describe a simple method predict identify resulting hybrid...
We present a detailed analysis of the temperature dependence thermal conductivity ferroelectric PbTiO3 thin film deposited in composition-spread geometry enabling continuous range compositions from ∼25% titanium deficient to ∼20% rich be studied. By fitting experimental results Debye model we deconvolute and quantify two main phonon-scattering sources system: domain walls (DWs) point defects. Our prove that DWs are agent limiting this system, not only stoichiometric region ([Pb]/[Ti] ≈ 1)...
Transition metal carbides exhibit a variety of interesting material properties, including electrochemical stability. When combined with precious metals, Ta and W have shown promise as fuel cell electrode materials; yet, the phase behavior these metal−carbide systems is largely unexplored. We investigated P-M-C P = Pt, Pd, Ru M using composition spread thin films. attained limited control deposited carbide through variation sputter atmosphere demonstrated decreased corrosion W−C materials...
In this paper, the pore filling of spiro-MeOTAD (2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)9, 9'-spirobifluorene) in mesoporous TiO<sub>2</sub> films is quantified for first time using XPS depth profiling and UVVis absorption spectroscopy. We show that spiro-OMeTAD can penetrate entire film, its concentration constant throughout film. determine a 2.5-•m-thick volume pores 60-65% filled. The become less filled when thicker are used. Such fraction much higher than solution because...
We present a detailed analysis of the temperature dependence thermal conductivity ferroelectric PbTiO3 thin film deposited in composition-spread geometry enabling continuous range compositions from ~25% titanium-deficient to ~20% titanium-rich be studied. By fitting experimental results Debye model we deconvolve and quantify two main phonon scattering sources system: domain walls (DWs) point defects. Our prove that DWs are agent limiting this system, not only stoichiometric region...