Following graphene growth by thermal decomposition of ethylene on Ir(111) at high temperatures we analyzed the strain state and the wrinkle formation kinetics as function of temperature. Using the moiré spot separation in a low energy electron diffraction pattern as a magnifying mechanism for the difference in the lattice parameters between Ir and graphene, we achieved an unrivaled relative precision of ±0.1 pm for the graphene lattice parameter. Our data reveals a characteristic hysteresis of the graphene lattice parameter that is explained by the interplay of reversible wrinkle formation and film strain. We show that graphene on Ir(111) always exhibits residual compressive strain at room temperature. Our results provide important guidelines for strategies to avoid wrinkling.
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http://dx.doi.org/10.1021/nl203530t | DOI Listing |
Nanomaterials (Basel)
December 2024
Guangdong Provincial Key Laboratory of Electronic Functional Materials and Devices, Huizhou University, Huizhou 516007, China.
W-doped ZnO (WZO) films were deposited on glass substrates by using RF magnetron sputtering at different substrate bias voltages, and the relationships between microstructure and optical and electrical properties were investigated. The results revealed that the deposition rate of WZO films first decreased from 8.8 to 7.
View Article and Find Full Text PDFJ Chem Phys
December 2024
Saha Institute of Nuclear Physics, A CI of Homi Bhabha National Institute, 1/AF, Bidhannagar, Kolkata 700064, India.
In this paper, we present a detailed investigation of the structural, magnetic, and electrical transport properties of Eu2-xCuxRu2O7 (x = 0, 0.2, 0.4) pyrochlores.
View Article and Find Full Text PDFPract Radiat Oncol
December 2024
Mayo Clinic, Department of Radiation Oncology, Rochester, MN 55905.
Objectives: Spatially fractionated radiation therapy (SFRT) intentionally delivers a heterogeneous dose distribution characterized by alternating regions of high and low doses throughout a tumor. This modality may enhance response to subsequent whole tumor radiation in bulky and radioresistant lesions that are historically less responsive to conventional radiation doses alone. The current study presents a single institution experience with modern era SFRT using predominantly a volumetric modulated arc therapy (VMAT) lattice technique.
View Article and Find Full Text PDFACS Nano
December 2024
Nanochemistry, Istituto Italiano di Tecnologia, Via Morego 30, Genova 16163, Italy.
We report the synthesis of ethylammonium lead iodide (EAPbI) colloidal nanocrystals as another member of the lead halide perovskites family. The insertion of an unusually large -cation (274 pm in diameter) in the perovskite structure, hitherto considered unlikely due to the unfavorable Goldschmidt tolerance factor, results in a significantly larger lattice parameter compared to the Cs-, methylammonium- and formamidinium-based lead halide perovskite homologues. As a consequence, EAPbI nanocrystals are highly unstable, evolving to a nonperovskite δ-EAPbI polymorph within 1 day.
View Article and Find Full Text PDFNanoscale Adv
December 2024
Institute of Science and Technology, TNU-University of Sciences Thai Nguyen Vietnam
This article studies the synthesis, as well as the structural, vibrational, and optical properties of Eu-doped ZnO quantum dots (QDs) and investigates the energy transfer mechanism from the ZnO host to Eu ions using Reisfeld's approximation. Eu-doped ZnO QDs at varying concentrations (0-7%) were successfully prepared using a wet chemical method. The successful doping of Eu ions into the ZnO host lattice, as well as the composition and valence states of the elements present in the sample, were confirmed through X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses.
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