Possible complete miscibility of (BN)x(C2)1−x(BN)_x(C_2)_{1-x} alloys

The stabilities of $(BN)_x(C_2)_{1-x}$ alloys and related superlattices are investigated by ab initio pseudopotential calculations. We find that the $(BN)_1/(C_2)_1$ superlattices in (111) orientations have the lowest formation energy among many short-range ordered $BNC_2$ structures due to the smallest number of B-C and C-N bonds. Based on the calculated formation energies at several compositions and for various ordered structures and assuming thermodynamic equilibrium, the solid solution phase diagram of $(BN)_x(C_2)_{1-x}$ alloys is constructed. We find that the complete miscibility of $(BN)_x(C_2)_{1-x}$ alloys is possible, which is in contrast with previous theoretical predictions but in agreement with experimental reports.Comment: 6 pages, 3 figure

Adsorbate-induced reconstructions and nanostructures on high-index copper surfaces

High-index copper surfaces generally show a strong tendency to reconstruct, forming one- or even two-dimensional periodic nanostructures. In this paper, a survey will be presented of the various oxygen-induced reconstructions reported on high-index copper surfaces. In particular, the reconstructions of the Cu(210)-O system are presented, as revealed by low-energy electron diffraction (LEED) and scanning tunnelling microscopy (STM). The adsorption of oxygen leads to a series of (n X 1) (n = 4,3,2) surface reconstructions, the Cu(210)-(2 x 1)O structure being the most stable. Quantitative LEED analysis confirms an added row model comprising Cu-O-Cu rows along the [001] direction on the topmost layer with oxygen at the long bridge sites. A range of faceting behaviour and nanostructure formation is also observed for the Cu(210)-O and Cu(210)-Br systems, and compared with other high- and low-index Cu surfaces. Copyright (C) 2001 John Wiley & Sons

The structural and electronic properties of (AlN)x(C2)1-x and (AlN)x(BN)1-x alloys

10.1088/0953-8984/13/22/322Journal of Physics Condensed Matter13225295-5311JCOM

Simulations of x-ray photoelectron diffraction experiment from theoretical calculations

10.1016/S0218-625X(01)00143-9Surface Review and Letters85549-557SRLE

Trends in bonding configuration at SiC/III-V semiconductor interfaces

10.1063/1.1402162Applied Physics Letters79111643-1645APPL

Study of electronic properties and bonding configuration at the BN/SiC interface

10.1016/S0368-2048(00)00365-0Journal of Electron Spectroscopy and Related Phenomena114-116483-488JESR

The evolution of 3 x 3, 6 x 6, root 3 x root 3R30 degrees and 6 root 3 x 6 root 3R30 degrees superstructuves on 6H-SiC (0001) surfaces studied by reflection high energy electron diffraction

The technique of reflection high energy electron diffraction (RHEED) has been applied to study the evolution of various superstructures on 6H-SiC (0 0 0 1) as a function of annealing temperature. Between the evolution of the stable 3 x 3 and root3 x root 3R30 degrees phases on a silicon-enriched 6H-SiC (0 0 0 1), a mixed phase 3 x 3/2 x 2 reconstruction followed by a well-defined 6 x 6 reconstruction was observed by RHEED for the first time. The 6 x 6 reconstruction is distinct from the pseudo-periodic 6 x 6 structure suggested previously for graphite moire pattern on 6H-SiC (0 0 0 1) [Surf. Sci. 48 (1975) 463; Surf. Sci. 256 (1991) 354]. The mechanisms for the formation of these superstructures in the sequence of 3 x 3, 6 x 6, root3 x root 3R30 degrees and 6 root3 x 6 root 3R30 degrees between 800 degreesC to 1200 degreesC were discussed. The 6 x 6 structure is proposed to evolve directly from the 3 x 3 following the missing of consecutive Si clusters in the twisted silicon adlayer model. Annealing the 6 x 6 reconstructed surface to 1000 degreesC gives rise to a root3 x root 3R30 degrees reconstruction From here, the segregation of carbon domains occurs readily and these form an incommensurate 6 root3 x 6 root 3R30 epilayer at 1200 degreesC. At the early stages of the annealing, the 6 root3 x 6 root 3R30 RHEED pattern consists of a series of cluster satellite streaks superimposed on 1 x I SiC. Further annealing results in the appearance of graphite streaks with its basis vectors rotated 30 degrees to SiC. Prolonged annealing of the graphitized surface results in the growth of single crystalline graphite multilayers on the 6H-SiC substrate. (C) 2001 Published by Elsevier Science B.V

Relaxation of Cu(100), (110) and (111) surfaces using AB initio pseudopotentials

10.1016/S0218-625X(01)00142-7Surface Review and Letters85541-547SRLE