scholarly journals Coverage dependent adsorption sites in the K/Cu(100) system: A crystal truncation rod analysis

1993 ◽  
Vol 208 (1) ◽  
Author(s):  
H. L. Meyerheim ◽  
I. K. Robinson ◽  
V. Jahns ◽  
P. J. Eng ◽  
W. Moritz
Keyword(s):  
Crystal Surface ◽  
High Coverage ◽  
Adsorption Sites ◽  
System A ◽  
Crystal Truncation Rod ◽  
Surface Crystal

AbstractThe analysis of the intensity along the diffraction rods normal to the crystal surface (crystal truncation rods) has been used to analyse the adsorption sites of potassium atoms adsorbed atAt high coverage (

scholarly journals Coverage dependent adsorption sites in the K/Cu(100) system: A crystal truncation rod analysis

1993 ◽  
Vol 208 (1-2) ◽  
Author(s):  
H. L. Meyerheim ◽  
I. K. Robinson ◽  
V. Jahns ◽  
P. J. Eng ◽  
W. Moritz
Keyword(s):  
Adsorption Sites ◽  
System A ◽  
Crystal Truncation Rod

On the adsorption sites for CO on the Rh(111) single crystal surface

1997 ◽  
Vol 371 (2-3) ◽  
pp. 381-389 ◽  
Author(s):  
A. Beutler ◽  
E. Lundgren ◽  
R. Nyholm ◽  
J.N. Andersen ◽  
B. Setlik ◽  
...  
Keyword(s):  
Single Crystal ◽  
Crystal Surface ◽  
Single Crystal Surface ◽  
Adsorption Sites

Adsorption Sites and Surface Reconstruction of the c (6 × 2)O/Cu(110) System: A SEXAFS Study

1990 ◽  
Vol 12 (3) ◽  
pp. 247-252 ◽  
Author(s):  
B Hillert ◽  
L Becker ◽  
M Pedio ◽  
J Haase
Keyword(s):  
Surface Reconstruction ◽  
Adsorption Sites ◽  
System A

scholarly journals Solvent fluctuations in the solvation shell determine the activation barrier for crystal growth rates

2019 ◽  
Vol 116 (48) ◽  
pp. 23954-23959 ◽  
Author(s):  
Anish V. Dighe ◽  
Meenesh R. Singh
Keyword(s):  
Glutamic Acid ◽  
Growth Rates ◽  
Crystal Surface ◽  
Activation Barrier ◽  
Hydration Number ◽  
Solvation Shell ◽  
Quasi Equilibrium ◽  
Acid Molecule ◽  
Crystalline Materials ◽  
Adsorption Sites

Solution crystallization is a common technique to grow advanced, functional crystalline materials. Supersaturation, temperature, and solvent composition are known to influence the growth rates and thereby properties of crystalline materials; however, a satisfactory explanation of how these factors affect the activation barrier for growth rates has not been developed. We report here that these effects can be attributed to a previously unrecognized consequence of solvent fluctuations in the solvation shell of solute molecules attaching to the crystal surface. With increasing supersaturation, the average hydration number of the glutamic acid molecule decreases and can reach an asymptotic limit corresponding to the number of adsorption sites on the molecule. The hydration number of the glutamic acid molecule also fluctuates due to the rapid exchange of solvent in the solvation shell and local variation in the supersaturation. These rapid fluctuations allow quasi-equilibrium between fully solvated and partially desolvated states of molecules, which can be used to construct a double-well potential and thereby to identify the transition state and the required activation barrier. The partially desolvated molecules are not stable and can attach spontaneously to the crystal surface. The activation barrier versus hydration number follows the Evans–Polanyi relation. The predicted absolute growth rates of the α-glutamic acid crystal at lower supersaturations are in reasonable agreement with the experimental observations.

First Principle Study of Hydrazine and OH- Co-Adsorption on Ni(111) in High Coverage System

2014 ◽  
Vol 893 ◽  
pp. 35-38 ◽  
Author(s):  
Andam Deatama Refino ◽  
Mohammad Kemal Agusta ◽  
Hermawan Kresno Dipojono ◽  
Nugraha
Keyword(s):  
Density Functional ◽  
Co Adsorption ◽  
Stable Configuration ◽  
Nickel Surface ◽  
Gauche Conformation ◽  
High Coverage ◽  
Adsorption Mechanisms ◽  
Adsorption Sites ◽  
The Stability ◽  
In Cis

Theoretical investigation of co-adsorption process between hydrazine (N2H4) and OH- on Ni(111) is performed using density functional theory. OH- adsorption mechanisms at various adsorption sites as well as its interaction with hydrazine in various conformations (anti, cis, and gauche) are studied. The stability of OH- adsorption on nickel surface is significantly influenced by the presence of hydrazine molecule. Among the three conformations of hydrazine, OH- adsorption on nickel surface doesn't occur in cis conformation. Otherwise, co-adsorption occurs in system with gauche and anti conformation. In anti system, hydrazine conformation is transformed during relaxation process and forms gauche conformation as the most stable configuration of the system.

Research of an Open CNC System of Machine Tool for Finding and Repairing Surface Damage on KDP Crystal

2014 ◽  
Vol 800-801 ◽  
pp. 531-536
Author(s):  
Ming Jun Chen ◽  
Lin Xi Jiang ◽  
Ze Xuan Zuo ◽  
Yong Xiao
Keyword(s):  
Crystal Surface ◽  
Surface Damage ◽  
Numerical Control ◽  
Cnc System ◽  
Kdp Crystal ◽  
Open Cnc ◽  
System A ◽  
Efficient Detection ◽  
Ultra Precision ◽  
Open Cnc System

In order to find and repair surface damage on KDP crystal, an open computer numerical control(CNC) system has been developed. This paper introduces the hardware structure of the control system, explains the development of an open CNC system software, which has friendly human-machine interface (HMI) and can make the finding and repairing process efficiently and conveniently and also expounds the algorithm and related parameters for servo tuning. With the open CNC system, the process of finding surface damage is accomplished in 3 hours and clear images of crystal surface damage is taken by CCD. And also, with the help of the open CNC system, a 600µm-diameter, 25µm-depth Gaussian repair contour with low roughness is obtained. Experimental results prove that the open CNC system for finding and repairing surface damage on KDP crystal meets the requirement of efficient detection and ultra-precision machining.

Polymorphic crystalline wetting layers on crystal surfaces

2021 ◽  
Author(s):  
Xipeng Wang ◽  
Bo Li ◽  
Mengmeng Li ◽  
Yilong Han
Keyword(s):  
Crystal Surface ◽  
Surface Phenomena ◽  
Surface Wetting ◽  
Crystal Surfaces ◽  
Crystalline Layer ◽  
Coherent Interface ◽  
Wetting Layers ◽  
Double Surface ◽  
Surface Crystal ◽  
Surface Layer Thickness

Abstract Analogous to surface premelting, we propose that a crystal surface can undergo a pre-solid-solid transition, i.e. developing a thin polymorphic crystalline layer before reaching the solid-solid transition temperature if two crystals can form a low-energy coherent interface. We confirm this in simulations and colloid experiments at single-particle resolution. The power-law increase of surface layer thickness is analogous to premelting. Different kinetics and reversibilities of surface-crystal growth are observed in various systems. Surface crystals exist not only under thermal equilibrium, but also during melting, crystallization, and grain coarsening. Furthermore, the premelting and pre-solid-solid transition can coexist, resulting double surface wetting layers. We hypothesize that such surface phenomena exist in atomic and molecular crystals, which provide a novel way to tune material properties.

Calculation of crystal truncation rod structure factors for arbitrary rational surface terminations

2002 ◽  
Vol 35 (6) ◽  
pp. 696-701 ◽  
Author(s):  
Thomas P. Trainor ◽  
Peter J. Eng ◽  
Ian K. Robinson
Keyword(s):  
Coordinate System ◽  
Reciprocal Lattice ◽  
Rational Surface ◽  
Cell Geometry ◽  
System A ◽  
Surfaces And Interfaces ◽  
Crystal Truncation Rod ◽  
Structure Factors ◽  
Rational Plane ◽  
Crystalline Surfaces

The technique of crystal truncation rod (CTR) diffraction is widely used for studying the structure of crystalline surfaces and interfaces. The theory and experimental details of the technique are well established; however, published methods for structure-factor calculations are typically based on a simple surface cell geometry. A method is presented for determining a surface coordinate system which results in a reciprocal lattice that is simply defined in terms of the surface termination. Based on this surface coordinate system, a general formalism for the calculation of CTR structure factors is re-derived, which may be easily applied to any surface that can be represented as a rational plane of a bulk crystal system.

Sign in / Sign up

Export Citation Format

Share Document