BaMgAl10O17:Eu2+ (BAM) phosphors used for plasma display panels and three-band fluorescence lamps are exposed to an oxidizing environment at about 500 degrees C, which is currently unavoidable in actual applications. We investigated the mechanism of the luminance degradation of BAM caused by annealing at 500 degrees C based on the difference in luminance degradation of bulk particle and nanoparticle samples under various excitation source irradiations. When the samples were excited by the different light sources, more than 30% degradation of luminance occurred under 147 nm while less than 10% degradation occurred under 254 nm both for nanoparticle and bulk particle samples. In addition, the luminescence degradation of nanophosphors shows a different tendency compared to the bulk phosphors. With a model based on the particle size and excitation light penetration depth, we demonstrate that the degradation is still mainly ascribed to the oxidized of divalent Eu. The differences in luminescence properties between nanophosphors and bulk phosphors are also illustrated by this model. As a result, the potential industrial applications of nanophosphors are evaluated.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1166/jnn.2014.8011 | DOI Listing |
ACS Nano
January 2025
Battery and Electrochemistry Laboratory (BELLA), Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, Karlsruhe 76131, Germany.
Improving interfacial stability between cathode active material (CAM) and solid electrolyte (SE) is vital for developing high-performance all-solid-state batteries (ASSBs), with compatibility issues among the cell components representing a major challenge. CAM surface coating with a chemically inert ion conductor is a promising approach to suppress side reactions occurring at the cathode interfaces. Another strategy to mitigate mechanical degradation involves utilizing single-crystalline particle morphologies.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
University of Tokyo, Institute for Solid State Physics, Kashiwa, Chiba 277-8581, Japan.
Non-Hermiticity gives rise to distinctive topological phenomena absent in Hermitian systems. However, connection between such intrinsic non-Hermitian topology and Hermitian topology has remained largely elusive. Here, considering the bulk and boundary as an environment and system, respectively, we demonstrate that anomalous boundary states in Hermitian topological insulators exhibit non-Hermitian topology.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Department of Physics, Indian Institute of Technology (IIT) Delhi, New Delhi 110016, India.
The concept of inert matrix fuel (IMF) has been proposed to utilize the energetic value of Pu and transmute minor actinides in nuclear reactors. In order to offset the initial reactivity of nuclear fuel, gadolinium (Gd) is employed as a burnable poison, owing to its high neutron absorption cross-section. To gain insights into the radiation stability and influence of grain boundaries on irradiation behaviour, 5 mol% Gd-doped ceria samples, sintered at varying temperatures, were subjected to irradiation using 400 Kr ions.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
January 2025
Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
Using many-body perturbation theory, we study the optical properties of phenylthiolate-capped cadmium sulfide nanoparticles to understand the origin of the experimentally observed blue shift in those properties with decreasing particle size. We show that the absorption spectra predicted by many-body perturbation theory agree well with the experimentally measured spectra. The results of our calculations demonstrate that all low-energy excited states correspond to a mixture of two fundamental types of excitations: intraligand and ligand-to-metal charge-transfer excitations.
View Article and Find Full Text PDFMar Environ Res
January 2025
Channel Islands National Marine Sanctuary, United States.
The Southern California Bight is an ecologically important region for many local and migratory fauna. We combine bulk and compound-specific amino acid stable isotope measurements in the skeletons of proteinaceous octocorals with new regional ocean modeling system model output to explore biogeochemical changes at two locations within the Bight - Santa Cruz Basin and Santa Barbara Channel. Separated by the Channel Islands, these sites display distinct oceanographic regimes.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!