Glancing angle ion bombardment during thin film deposition is shown to have a pronounced alignment effect on crystallographic orientation. Restricted fiber texture achieved in Nb films deposited at room temperature onto amorphous silica substrates by Ar beam sputtering, with simultaneous 200 eV Ar+ ions 20° from glancing angle. The direction corresponds channeling for the incident between (110) planes, which low sputtering yield expected. degree of measured as function ion/atom arrival rate...

Glancing angle ion bombardment during thin-film deposition is shown to have a pronounced alignment effect on crystallographic orientation. Restricted fiber texture achieved in Nb films deposited at room temperature onto amorphous silica substrates by Ar beam sputtering, with simultaneous 200 eV Ar+ ions 20° from glancing angle. The direction corresponds channeling for the incident between (110) planes, which low sputtering yield expected. degree of measured as function ion/atom arrival rate...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRational design of a heterogeneous palladium catalyst for the selective hydrogenation alkynesJudith G. Ulan, Wilhelm F. Maier, and David A. SmithCite this: J. Org. Chem. 1987, 52, 14, 3132–3142Publication Date (Print):July 1, 1987Publication History Published online1 May 2002Published inissue 1 July 1987https://pubs.acs.org/doi/10.1021/jo00390a032https://doi.org/10.1021/jo00390a032research-articleACS PublicationsRequest reuse permissionsArticle...

We present a comparison of three different methods to calibrate the spring constant two types silicon beam shaped atomic force microscope (AFM) cantilevers determine each method's accuracy, ease use and potential destructiveness. The majority research in calibrating AFM has been concerned with contact mode levers. levers we have studied are used modulation tapping air. Not only can these constants an order magnitude greater than levers, but also their geometries be quite from standard...

Abstract The structure of the epitaxial Pd2Si/(111)Si interface has been investigated by transmission electron microscopy. Observations normal to using weak-beam technique demonstrate presence misfit dislocations and support a model where atomically smooth regions are coherent associated with interfacial steps. High-resolution lattice images (110) cross-sectional specimens consistent this model, showing characteristic image features which may be explained theoretical multislice simulations....

What can world-systems analysis of the role Africa in creation capitalist world-economy tell us about Amazon’s model control global supply chains 21st century? How did patterns established by European imperialism and enslavement Africans create long-lasting continuities racial capitalism migration that are used Amazon to profit contemporary era? We argue analyses racialized labor underlay world-system presented Wallerstein, Rodney, others, most notably Cedric Robinson, help understand...

The control of hydroxyapatite crystal initiation and growth during enamel development is thought to be mediated by the proteins extracellular matrix. However, precise nature these critical mineral−protein interactions remains obscure. In this study, fluid tapping mode atomic force microscopy was used image, for first time, binding found in matrix (amelogenin albumin) developing crystals. Both albumin amelogenin were associated with surfaces under conditions close physiological; however, two...

The small size (58 residues) and simple structure of the B domain staphylococcal protein A (BdpA) have led to this being a paradigm for theoretical studies folding. Experimental folding BdpA been limited by rapidity its kinetics. We report kinetics fluorescent mutant (G29A F13W), named F13W * , using nanosecond laser-induced temperature jump experiments. Automation apparatus has permitted large data sets be acquired that provide excellent signal-to-noise ratio over wide range experimental...

The adhesion force between two 11-amino-1-undecanethiol self-assembled monolayers has been measured as a function of pH in solutions ionic strengths, high (10-1 M) and low (10-4 M). In strength solutions, the titration curve approximates to sigmoidal step, centered at ca. 3, with negligible (20 nN) higher but previously unobserved drop almost zero above 12. shape is radically different, comprising peaks 6 10. length alkyl spacer strong effect on magnitude peak which increases significantly...

The control of hydroxyapatite crystal initiation and growth during enamel development is thought to be mediated via the proteins extracellular matrix. However, precise nature these matrix-mineral interactions remains obscure. aim present study was use a combination atomic chemical force microscopy characterize developing surfaces determine their relationship with endogenous matrix protein (amelogenin). results show regular discrete domains various charges or charge densities on crystals...

We report on single molecule measurements of the viscoelastic properties polysaccharide dextran using a new approach which involves acquiring power spectral density thermal noise an atomic force microscope cantilever while holding interest under force-clamp conditions. The attractiveness this when compared with techniques use forced oscillations constant loading rate conditions is that it near-equilibrium measure mechanical response provides more relevant probe thermally driven biomolecular...

SUMMARY This paper describes how a transmission electron microscope may be used to study rigid body displacements between coincidence related grains. Computer calculations have predicted that such reduce grain boundary internal energy in metals by relieving atomic over‐crowding. Displacements are revealed as fringe patterns Bloch wave interference mechanism resembling which gives rise stacking fault fringes. The sensitivity of the technique detecting very small and its potential applications...

There is a suggestion from computer ca1culatons of grain boundary energy that the minimum in may be associated with an orientation relationship which includes translation one lattice addition to rotation.Coincidence orientations are characterized by rotation matrices consist rational elements. It follows all directions rotated into coincidence other directions. In particular it common occurrence for planes same form but different grains parallel. absence such continuous across boundary....

During the secretory stage of enamel development, hydroxyapatite crystals appear as thin ribbons which grow substantially in width and thickness during later maturation stage. In this study, atomic force microscope (AFM) was used to investigate developmentally-related changes deproteinized crystal surface topography normal animals those receiving daily doses fluoride. The AFM revealed previously undescribed surfaces features, some may represent growth sites or different crystalline phases....

The present article describes the preparation and preliminary characterization of a novel phosphate-functionalized self-assembled monolayer (SAM) determination surface ionization states phosphate headgroup in aqueous solutions by chemical force microscopy (CFM). used was PO(OH)2, diprotic acid. adhesion between an AFM probe flat substrate, both which were chemically modified with same SAM, also measured as function pH ionic strength. At low strength (10(-4) M), two peaks observed titration...