The equilibrium thermal roughening of thin Ge layers (one and two monolayers) deposited on Si(001) has been investigated with low-energy electron microscopy. A Ge-coverage-dependent roughening is observed. For two monolayers, the temperature at which imaging contrast is lost due to surface roughness is 900+/-25 degrees C, between the roughening temperatures of Ge(001) and Si(001). Lower Ge coverages move this temperature closer to that of Si(001). The roughening is confined to the Ge overlayers. It is believed that this phenomenon represents a new type of surface roughening transition that should be generally applicable for heteroepitaxial films.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.85.2152 | DOI Listing |
Nanoscale Adv
December 2024
Department of Chemistry and Biochemistry, University of Arkansas Fayetteville AR 72701 USA
The use of metal oxide catalysts to enhance plasma CO reduction has seen significant recent development towards processes to reduce greenhouse gas emissions and produce renewable chemical feedstocks. While plasma reactors are effective at producing the intended chemical transformations, the conditions can result in catalyst degradation. Atomic layer deposition (ALD) can be used to synthesize complex, hierarchically structured metal oxide plasma catalysts that, while active for plasma CO reduction, are potentially vulnerable to degradation due to their high surface area and nanoscopic thickness.
View Article and Find Full Text PDFPhys Rev E
November 2024
Grupo Interdisciplinar de Sistemas Complejos (GISC), Departamento de Matemáticas, Universidad Carlos III de Madrid, 28911 Leganés, Madrid, Spain.
Systems of oscillators subject to time-dependent noise typically achieve synchronization for long times when their mutual coupling is sufficiently strong. The dynamical process whereby synchronization is reached can be thought of as a growth process in which an interface formed by the local phase field gradually roughens and eventually saturates. Such a process is here shown to display the generic scale invariance of the one-dimensional Kardar-Parisi-Zhang universality class, including a Tracy-Widom probability distribution for phase fluctuations around their mean.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
College of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou 450001, PR China; National & Local Joint Engineering Research Center of Cereal-Based Foods (Henan), Zhengzhou 450001, PR China. Electronic address:
This study investigated the interaction between yam starch (YS) and soy protein isolate hydrolysate (SPH), and their effects on in vitro digestibility of starch through extrusion treatment. Results indicated that SPH with 6 % hydrolysis degree had the lowest relative molecular mass. X-ray diffraction and Raman spectroscopy revealed an increase in the relative crystallinity of extruded yam starch (EYS) from 17.
View Article and Find Full Text PDFBMC Oral Health
November 2024
Department of Prosthodontics, Faculty of Dentistry, Karadeniz Technical University, Trabzon, Turkey.
Background: To investigate the effects of thermal cycling and surface treatment methods on the bonding effectiveness of multi-step resin cements to CAD/CAM blocks.
Methods: A total of 198 slices, 66 each from CAD/CAM blocks (feldspathic ceramic: Vitablocs TriLuxe Forte, V; resin matrix ceramics (RMCs): Cerasmart, C; and Shofu Block HC, S), were obtained and randomly divided into two subgroups for etching with hydrofluoric acid (HFA) and sandblasting with AlO (SB). After the surface treatments, one etched and one sandblasted sample of each CAD/CAM block was observed via SEM analysis at 500× magnification.
J Prosthodont
August 2024
Department of Prosthodontics, Faculty of Dentistry, Istanbul Medipol University, Istanbul, Turkey.
Purpose: The aim of this study was to evaluate the impact of mechanical roughening, adhesive applications, and aging on the bonding between CAD-CAM denture base materials with distinct chemical contents and hard relining material.
Materials And Methods: A total of 300 denture base specimens were produced by additive, subtractive, and conventional heat-polymerization techniques (N = 100). The specimens have been classified into five subgroups based on the particular surface treatments administered (n = 20): (1) Hard relining material's adhesive application (control); (2) Tungsten carbide bur application for 1 min, and hard reline material's adhesive application; (3) Airborne-particle abrasion (APA) with 110 μm AlO, and hard reline material's adhesive application; (4) Scotchbond Universal application; and (5) Visio.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!