Resolution is a key parameter for microscopy, but methods for standardizing its definition are often poorly defined. For a developing technique such as scanning helium microscopy, it is critical that a consensus-based protocol for determining instrument resolution is prepared as a written standard to allow both comparable quantitative measurements of surface topography and direct comparisons between different instruments. In this paper we assess a range of quantitative methods for determining instrument resolution and determine their relative merits when applied to the specific case of the scanning helium microscope (SHeM). Consequently, we present a preliminary protocol for measuring the resolution in scanning helium microscopy based upon utilizing appropriate test samples with sets of slits of well-defined dimensions to establish the quantitative resolution of any similar instrument.
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http://dx.doi.org/10.1016/j.ultramic.2021.113453 | DOI Listing |
Microsc Res Tech
January 2025
USPCAS-W, Mehran University of Engineering and Technology, Jamshoro, Pakistan.
Nanomaterials have been gaining interest due to their remarkable properties at the nanoscale. The surface area of particles becomes high at the nanoscale because of this virtue, they have been used in a bundle of applications like electronics, biomedical, agriculture, wastewater treatment, semiconductor industry, cosmetics, drug delivery, paints, and so forth. The morphology (size and shape) of nanomaterials plays an important role because each application requires the appropriate morphology for better performance.
View Article and Find Full Text PDFMol Cancer Ther
December 2024
National Center for Tumor Diseases, Heidelberg, Germany.
Ultra-high dose rate radiotherapy with electrons and protons has shown potential for cancer treatment by effectively targeting tumors while sparing healthy tissues (FLASH effect). This study aimed to investigate the potential FLASH sparing effect of ultra-high-dose rate helium ion irradiation, focusing on acute brain injury and subcutaneous tumor response in a preclinical in vivo setting. Raster-scanned helium ion beams were used to compare the effects of standard dose rate (SDR at 0.
View Article and Find Full Text PDFRev Sci Instrum
December 2024
2nd Institute of Physics B and JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany.
Low-temperature scanning tunneling spectroscopy is a key method to probe electronic and magnetic properties down to the atomic scale, but suffers from extreme vibrational sensitivity. This makes it challenging to employ closed-cycle cooling with its required pulse-type vibrational excitations, albeit this is mandatory to avoid helium losses for counteracting the continuously raising helium prices. Here, we describe a compact ultra-high vacuum scanning tunneling microscope (STM) system with an integrated primary pulse tube cooler (PTC) for closed-cycle operation.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Electrochemistry Department, St. Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg 199034, Russia.
In this work, a set of analytical techniques, including scanning electron microscopy (SEM), Raman scattering spectroscopy, X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray microanalysis (EDX) and cyclic voltammetry (CV), were used to study the impact of high-energy He ion irradiation on the structural and electrochemical characteristics of sulfur-containing multi-walled carbon nanotubes (S-MWCNTs) placed on a titanium substrate. The results indicate that the ion beam treatment of the S-MWCNT system led to an increase in the level of imperfections on the surface structures of the nanotubes due to the formation of point defects on their outer walls and the appearance of oxygen-containing functional groups, including SO groups, near these defects. At the same time, a significant increase in the sulfur concentration (by 6.
View Article and Find Full Text PDFMaterials (Basel)
November 2024
Department of Materials and Ceramic Engineering, CICECO-Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal.
External pressure is often applied during sintering to obtain materials with improved properties. For complex concentrated alloys (CCAs), this processing step is commonly performed in vacuum. However, this can promote the evaporation of elements and increase the oxide content, thereby degrading the properties of the alloy.
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