The exchange interactions in polycrystalline samples of Ca1-xLaxMnO3 (0.00< or =x< or =0.05) are studied by means of Raman scattering and electron paramagnetic resonance. Dramatic reductions in the spin-phonon interactions and magnetic correlations are observed for La doping levels as small as approximately 2%-3%. These results show that the charge carriers play an important role in the overall exchange coupling in the electron-doped manganites, even at very low doping levels.
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http://dx.doi.org/10.1103/PhysRevLett.86.5385 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
Hydrogen production via water-splitting or ammonia electrolysis using transition metal-based electrodes is one of the most cost-effective approaches. Herein, ca. 1-4% of Pt atoms are stuffed into a wolframite-type NiWO lattice to improve the electrocatalytic efficiency.
View Article and Find Full Text PDFChem Asian J
January 2025
University of Macau, Institute of Applied Physics and Materials Engineering, MACAO.
In recent years, carbon dots (CDs) with fluorescence imaging function have been widely used in biomedicine, electronic manufacturing and environmental monitoring. However, monochromatic fluorescence is often limited by the application environment and loses its effectiveness. Here, we carefully designed white fluorescent CDs (WF-CDs) by solvothermal method, which is used for fluorescence imaging applications under different environmental conditions.
View Article and Find Full Text PDFSmall
January 2025
Engineering Research Center of Electronic Information Materials and Devices (Ministry of Education), Guangxi Key Laboratory of Information Materials, School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin, 541004, China.
In recent years, carbon-based printable mesoscopic perovskite solar cells (p-MPSCs) without hole transport layers have garnered considerable interest because of their outstanding benefits in terms of stability and cost. However, the use of carbon electrodes instead of hole transport materials and noble metal electrodes leads to energy level mismatch, which limits the power conversion efficiency (PCE) of p-MPSCs. In this work, a molecular doping strategy is proposed employing cyclopentylmethanamine to passivate surface and subsurface crystal defects in perovskite layers while inducing an energy shift toward the p-type in the perovskite region within carbon electrodes.
View Article and Find Full Text PDFIsotopes Environ Health Stud
January 2025
School of Chemistry and Physics, University of KwaZulu-Natal, Scottsville, South Africa.
This study presents an investigation into the natural radioactivity levels of U, Th, and K using a thallium-doped sodium iodide (NaI(TI)) detector and associated radiological hazards in river sediments, specifically sand, which serves as a crucial building material in the KwaZulu-Natal Province of South Africa. The assessment aims to provide insights into potential radiological risks posed by the utilization of these sediments in construction activities. The mean activity concentrations of U, Th, and K are 145.
View Article and Find Full Text PDFJ Mol Model
January 2025
Nanjing Hydraulic Research Institute, Shanghai, China.
Context: This study systematically investigated the effects of single S-atom vacancy defects and composite defects (vacancy combined with doping) on the properties of MoS using density functional theory. The results revealed that N-doped S-vacancy MoS has the smallest composite defect formation energy, indicating its highest stability. Doping maintained the direct band gap characteristic, with shifts in the valence band top.
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