Search results for "Note"
showing 10 items of 10709 documents
Single-shot ultrafast laser processing of high-aspect-ratio nanochannels using elliptical Bessel beams
2017
Ultrafast lasers have revolutionized material processing, opening a wealth of new applications in many areas of science. A recent technology that allows the cleaving of transparent materials via non-ablative processes is based on focusing and translating a high-intensity laser beam within a material to induce a well-defined internal stress plane. This then enables material separation without debris generation. Here, we use a non-diffracting beam engineered to have a transverse elliptical spatial profile to generate high aspect ratio elliptical channels in glass of dimension 350 nm x 710 nm, and subsequent cleaved surface uniformity at the sub-micron level.
Fluorinated Fullerene Molecule on Cu(001) Surface as a Controllable Source of Fluorine Atoms
2018
A coverage-dependent growth of well-ordered copper halogenide structures as a result of fluorinated fullerene molecule adsorption on Cu(001) surface has been studied by means of scanning tunneling ...
Ab initio calculations for the polar (0 0 1) surfaces of YAlO3
2018
Abstract The results of ab initio calculations of polar YAlO3 (0 0 1) surfaces by means of a hybrid B3LYP exchange-correlation functional as it is implemented in the CRYSTAL computer code are presented. Both polar YO and AlO2-terminations of the cubic YAlO3 (0 0 1) surface were considered. We performed relaxation of atoms on the upper three layers of both YO and AlO2-terminated YAlO3 (0 0 1) surfaces using in our calculations slabs containing 22 and 23 atoms as well as 9 layers, respectively. We predict a significant increase of the Al-O chemical bond covalency on the AlO2-terminated YAlO3 (0 0 1) surface with respect to the YAlO3 bulk. Our calculated YO and AlO2-terminated YAlO3 polar (0 0…
Disclosing the emissive surface traps in green-emitting carbon nanodots
2021
Abstract The bright photoluminescence of surface-functionalized carbon nanoparticles, known as carbon nanodots (CDs), has been studied for more than a decade because of its fundamental photo-physical interest and strong technological potential. However, the essential nature of the electronic states involved in their typical light emission remains very elusive. Here, we provide conclusive evidence that surface carboxylic moieties are the key to CD fluorescence. The synergy of nanosecond and femtosecond optical studies, cryogenic fluorescence, computational investigations and chemical engineering of a strategically chosen model CD system, allows to demonstrate that their visible-light transit…
Detailed photoluminescence study of vapor deposited Bi2S3 films of different surface morphology (Phys. Status Solidi B 11/2014)
2014
Quantitative description of C-60 diffusion on an insulating surface
2010
The diffusion of ${\text{C}}_{60}$ molecules on large, atomically flat terraces of the ${\text{CaF}}_{2}(111)$ surface is studied under ultrahigh vacuum conditions at various substrate temperatures below room temperature. The weak molecule-substrate interaction on this insulating surface makes a direct observation of hopping events difficult. Therefore, to determine a quantitative value of the diffusion barrier, we employ the so-called onset method. This method is based on the analysis of spatial properties of islands created by nucleation of diffusing ${\text{C}}_{60}$ molecules, as measured by noncontact atomic force microscopy. We first determine the critical cluster size to be ${i}^{\en…
Kirkwood–Buff Integrals Using Molecular Simulation: Estimation of Surface Effects
2020
Kirkwood&ndash
Quantitative atomic force microscopy
2017
A variety of atomic force microscopy (AFM) modes is employed in the field of surface science. The most prominent AFM modes include the amplitude modulation (AM) and the frequency modulation (FM) mode. Over the years, different ways for analyzing data acquired with different AFM modes have been developed, where each analysis is usually based on mode-specific assumptions and approximations. Checking the validity of the seemingly different approximations employed in the various analysis methods can be a tedious task. Moreover, a straightforward comparison of data analyzed with different methods can, therefore, be challenging. Here, we combine the existing evaluation methods which have been sep…
Standardisation, Reference Materials and Comparative Measurements for Surface Area and Pore Characterisation
1991
Summary This paper reviews current activities to standardise measuring procedures for surface area and pore size determination. Comparative measurements at different laboratories using candidate reference materials revealed that surfaces of highly dispersed materials can be affected remarkably during storing and sample preparation. On account of the fractal nature of these materials, the results depend on the measuring methods. Reference materials of dispersed materials are offered by national and international standardisation administrations and by industrial distributers. The standardisation of measuring methods becomes more and more international (ISO, IUPAC). The survey includes tables …
Engineering Proteins at Interfaces: From Complementary Characterization to Material Surfaces with Designed Functions
2018
Abstract Once materials come into contact with a biological fluid containing proteins, proteins are generally—whether desired or not—attracted by the material's surface and adsorb onto it. The aim of this Review is to give an overview of the most commonly used characterization methods employed to gain a better understanding of the adsorption processes on either planar or curved surfaces. We continue to illustrate the benefit of combining different methods to different surface geometries of the material. The thus obtained insight ideally paves the way for engineering functional materials that interact with proteins in a predetermined manner.