The quantum size effect (QSE) in electron reflectivity from Fe thin films grown on a W(110) surface precovered with a two monolayer Cu film has been investigated using spin polarized low energy electron microscopy. Spin-dependent QSE-induced oscillations in the reflected intensity occur with energy and film thickness. The series of intensity peaks that is observed identifies spin-dependent quantum well resonances in the Fe film that are sensitive to electronic band structure and details of the buried interface. Information about the spin-dependent unoccupied bands of the Fe film in the ΓΝ direction normal to the film plane is obtained by analyzing the observed quantum well resonance conditions. The spin-split bands that are determined are uniformly shifted downward by 1.7 eV compared to bulk-like bands determined previously in Fe films on a bare W(110) substrate by the same method. Evidence is also obtained that the buried interface that defines the thin film quantum well boundary is located one layer above the W(110) surface. These results suggest that the Cu layer in direct contact with the substrate remains largely intact, but the weakly-bound second Cu layer mixes or segregates freely.
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http://dx.doi.org/10.1016/j.ultramic.2015.02.006 | DOI Listing |
Natl Sci Rev
February 2025
Institute of Nanoscience and Applications, Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
Colloidal quantum dots (QDs) are solution-processable semiconductor nanocrystals with favorable optoelectronic characteristics, one of which is their multi-excitonic behavior that enables broadband polychromatic light generation and amplification from monodisperse QDs. However, the practicality of this has been limited by the difficulty in achieving spatial separation and patterning of different colors as well as the high pumping intensity required to excite the multi-excitonic states. Here, we have addressed these issues by integrating monodisperse QDs in multi-excitonic states into a specially designed cavity, in which the QDs exhibit an anisotropic polychromatic emission (APE) characteristic that allows for tuning the emission from green to red by shifting the observation direction from perpendicular to lateral.
View Article and Find Full Text PDFThe development of an effective and rapid method for healing the skin is of crucial importance. In this study, we prepared a porous scaffold made of polycaprolactone (PCL) and carbon quantum dots (CQDs), Fe, and Chitosan (Cs) as the scaffold core to cover the skin. Then evaluated antibacterial, biocompatibility, and wound healing properties as well as the expression of genes effective in wound healing.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
School of Chemistry and Chemical Engineering/Institute of Clean Energy and Materials/Guangzhou Key Laboratory for Clean Energy and Materials, Guangzhou University, Guangzhou Higher Education Mega Center, 230 Wai Huan Xi Road, Guangzhou, Guangdong 510006, People's Republic of China.
Intentional doping plays a pivotal role in customizing metal halides' electronic and optical features. This work manipulates the incorporation and distribution of Mn in Cu(I) halide by controlling the elemental steps involved in the growth-doping kinetics as well as investigates the localized lattice and electronic structures in different doping configurations. Complementary experimental and theoretical results demonstrate that a uniform and relatively high Mn doping level can be achieved by a step-tailored strategy that encompasses reducing the growth rate of the halide matrix, enhancing the surface adsorption of Mn, and facilitating the incorporation of the dopants.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Institute for Materials Discovery, University College London, London WC1E 7JE, U.K.
Paper is an ideal platform for creating flexible and eco-friendly electronic systems. Leveraging the synergistic integration of zero- and two-dimensional materials, it unfolds a broad spectrum of applications within the realm of the Internet of Things (IoT), spanning from wearable electronics to smart packaging solutions. However, for paper without a polymer coating, the rough and porous nature presents significant challenges as a substrate for electronics, and the absence of well-established fabrication methods further hinders its application in wearable electronics.
View Article and Find Full Text PDFBMJ Open
January 2025
Pharmaceutics and Social Pharmacy, Addis Ababa University College of Health Sciences, Addis Ababa, Ethiopia.
Objective: This study analysed the spatial and temporal patterns of cervical cancer incidence in Addis Ababa from 2012 to 2021.
Design: An ecological study was conducted from 1 September to 30 November 2023 to examine the spatiotemporal trends of cervical cancer incidence.
Setting: The research was conducted in Addis Ababa, the capital city of Ethiopia.
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