The dielectric properties of electrochemically grown zirconium oxide films by anodisation of zirconium in 1.0 mol dm-3 phosphoric acid solution were investigated in a 3 to 30 V potential range with a view to inducing surface modifications for eventual use in biomedical and electronic applications. The oxide films grown at different potentials were characterised by Atomic Force Microscopy, X-ray photoelectron and Raman spectroscopies; the latter demonstrated the incorporation of phosphate ions into the passive films. Flat band potentials calculated from the Mott-Shottky analysis of the oxides semiconducting properties confirm the bilayer structure of the films. The oxide dielectric permittivity was evaluated from impedance spectroscopy measurements and the film oxide model proposed gave values independent of the oxide growth potential.
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ACS Appl Opt Mater
December 2024
Department of Physics, Umeå University, Linnaeus väg 24, 901 87 Umeå, Sweden.
Multilayered metal-dielectric nanostructures display both a strong plasmonic behavior and hyperbolic optical dispersion. The latter is responsible for the appearance of two separated radiative and nonradiative channels in the extinction spectrum of these structures. This unique property can open plenty of opportunities toward the development of multifunctional systems that simultaneously can behave as optimal scatterers and absorbers at different wavelengths, an important feature to achieve multiscale control of light-matter interactions in different spectral regions for different types of applications, such as optical computing or detection of thermal radiation.
View Article and Find Full Text PDFSmall
January 2025
School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, China.
2D perovskite has demonstrated great potential for application in photovoltaic devices due to the tunable energy bands, suppressed ion migration, and high stability. However, 2D perovskite solar cells (PSCs) display suboptimal efficiency in comparison to 3D perovskite solar cells, which can be attributed to the quantum confinement and dielectric confinement effects resulting from the intercalation of organic spacer cations into the perovskite lattice. This review starts with the fundamental structural characteristics, optoelectronic properties, and carrier transport dynamics of 2D PSCs, followed by the discussion of approaches to improve the photovoltaic performance of 2D PSCs, including the manipulation of crystal orientation, phase distribution, pure phase, organic layer, and device engineering.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China; Department of Biological Systems Engineering, Washington State University, 213 L.J. Smith Hall, Pullman, WA 99164-6120, USA. Electronic address:
Whey protein (WP) is a highly nutritious animal protein, but its functional properties are sensitive to environmental factors, such as temperature, pH, and ionic strength, which prevent its applications in various food systems. The conjugation of proteins with polysaccharides via the Maillard reaction is an efficient method to improve their functionalities. The purpose of this study was to use radio frequency (RF) heating technology to assist the covalent coupling of WP and gum Arabic (GA) for improving their grafting efficiency and functional properties.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, Bellaterra 08193, Spain.
Nanolaminates based on ferroelectric polycrystalline doped HfO have gained interest because those compounds show enhanced functional properties. Here, we achieve coexisting improvement of remanent polarization and dielectric permittivity in wake-up-free epitaxial HfZrO/HfO nanolaminates with different numbers of HfO nanolayers if compared with HfZrO single films of equivalent thickness or other reported polycrystalline nanolaminates. Comprehensive structural characterization reveals that the origin of the enhancement must be the larger amount of the orthorhombic phase in the nanolaminates.
View Article and Find Full Text PDFMacromolecules
December 2024
Department οf Physics, University οf Ioannina, Ioannina 45110, Greece.
We report the pressure-temperature (-) phase diagram, the origin of the subglass dynamics, and the crystallization kinetics of the biobased polyester poly(ethylene 2,5-furanoate) (PEF), through dielectric spectroscopy (DS) measurements performed as a function of temperature and pressure. The phase diagram comprises four different "phases"; glass, quenched melt, crystalline, and normal melt. The cold crystallization temperature, , increases linearly with pressure (according to the Clausius-Clapeyron equation) as / ∼ 240 K·GPa and is accompanied by a small change in specific volume (Δ = 0.
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