The phase diagrams of continuous binary nanoalloys are important in providing guidance for material designs and industrial applications. However, experimental determination of the nano-phase diagram is scarce since calorimetric measurements remain quite challenging at the nanoscale. Based on the size-dependent cohesive energy model, we developed a unified nano-thermodynamic model to investigate...

We studied perceptual filling-in during maintained peripheral viewing of a uniform gray or red figure presented on a large textured background. Changes in the figure's size, shape, and eccentricity caused variations in the time required for filling-in that could be predicted from the size of its cortical projection within early visual areas. The data suggest that the time which elapsed before t...

Significant elemental segregation is shown to exist within individual hollow silver-gold (Ag-Au) bimetallic nanoparticles obtained from the galvanic reaction between Ag particles and AuCl4(-). Three-dimensional compositional mapping using energy dispersive X-ray (EDX) tomography within the scanning transmission electron microscope (STEM) reveals that nanoparticle surface segregation inverts fro...

We propose a theoretical explanation of the parallel and perpendicular lamellar orientations in free surface films of symmetric polystyrene-block-polybutadiene diblock copolymers on silicon substrates (with a native SiOx layer). Two approaches are developed: A correction to the strong segregation theory and a qualitative analysis of the intermediate segregation regime. We show that the perpendi...

Abstract The effect of the solid–wall boundary condition on the segregation behavior of a sand ternary mixture differing in size but having the same proportion has been investigated in a gas–solid bubbling fluidized bed. A multi-fluid computational fluid dynamics model incorporating the kinetic theory of granular flow has been used. The mass fraction profiles of the different-sized partic...

Abstract Phase separation and coarsening is a phenomenon commonly seen in binary physical and chemical systems that occur in nature. One model which takes into account additive stochastic noise is the Cahn-Hilliard-Cook (CHC) model. Often, the surface on which phase segregation occurs is not a flat surface. With this motivation, we present a semi-implicit numerical algorithm to solve the fourth...

An effective method for molecular beam epitaxial construction of metastable, pseudomorphic SnGe/ Ge~001! heterostructures is presented. This method exploits a surfactant species, Bi, to alter Sn surface-segregation kinetics. Using the x-ray standing wave technique, we demonstrate not only that Bi segregates to the growth surface more strongly than Sn, but that it also dramatically suppresses th...

It is common for the components in a homogeneous metallic alloy to separate at its surface. This phenomenon is known as surface segregation. For example, under certain conditions, the surface layer of atoms in a Cu85Pd15 is pure copper, while the second layer of atoms is 50% copper. The bulk retains its 85/15 composition. A depth-profile characterizes the surface segregation by describing the a...

The surface and near-surface chemical composition of electroceramic materials often shows significant deviations from that of the bulk. In particular, layered materials, such as cation-ordered LnBaCo2O(5+δ) perovskites (Ln = lanthanide), undergo surface and sub-surface restructuring due to the segregation of the divalent alkaline-earth cation. These processes can take place during synthesis and...

We investigate the effect of nanoscale variations in the surface roughness of individual particles on macroscale granular flow characteristics. Experiments were conducted in circular rotating tumblers with smooth and rough 2 and 3 mm steel particles. The smooth beads had a rms surface roughness of approximately 30 to 60 nm; rough beads had a surface roughness of approximately 240 to 350 nm. The...