Temperature dependent structure of low index copper surfaces studied by molecular dynamics simulation

Abstract

The thermal behavior of the (010), (110) and (111) copper surfaces is studied by molecular dynamics simulation. We have used a many-body potential based on the tight-binding model in order to describe the Cu-Cu interaction. The calculations we have performed correspond to simulations in the temperature range between 600 and 1800 K. The observed order in the stability follows the same order as in the packing density, i. e., (110), (010) and (111). The (110) disorder results from anharmonic effects and by vacancy-adatom formation. On the other end, the (111) surface is very stable, and remains so up to temperatures of the order of the bulk melting point. The melting proceeds by a layer-by-layer mechanism.

Surface Temperature Effects on Dissociative Chemisorption of H2 on Cu(100)

“…In the first expanded surface, to mimic the effect of the high T s we additionally allow the interlayer distance between the two topmost layers, d 12 , to increase relative to the bulk interlayer distance by the value obtained from MD simulations using a tight-binding model . Specifically, using linear interpolation of the MD tight-binding results for T s = 1000 and 1100 K resulted in an increase of d 12 of 2.0% over the 1030 K bulk interlayer distance, which translates into d 12 = 1.911 Å. For the second expanded surface, we used the value of d 12 obtained from our own AIMD simulations ( d 12 = 1.952 Å).…”

“…Values of the interaction energies are provided for this PES . Values are also provided of the interaction energies computed with the SRP48 functional for the static surface at 0 K, the expanded surface at T s = 1030 K using the δ d 12 value of ref , and the expanded surface using the δ d 12 value obtained from our AIMD simulations (4.2%) of the Cu(100) surface at T s = 1030 K.…”

Crystal Structure Evolution of Individual Graphene Islands During CVD Growth on Copper Foil

“…From these RHEED images, not only the variation of Cu grain orientation is evidenced, but also a disordered Cu surface is observed at a temperature below the bulk melting temperature of 1085 °C. The formation of the disordered surface layer caused by the surface pre‐melting usually occurs at temperatures below the bulk melting points, as it has been experimentally proven for many fcc metals (Pb, Al, and others), and theoretically predicted for low‐index Cu surfaces . The occurrence of this surface disorder depends on the packing density, and for Cu, it is most pronounced on open surfaces (e. g., Cu (110)) but less likely for a close‐packed surface (e. g., Cu (111)) .…”

“…The formation of the disordered surface layer caused by the surface pre‐melting usually occurs at temperatures below the bulk melting points, as it has been experimentally proven for many fcc metals (Pb, Al, and others), and theoretically predicted for low‐index Cu surfaces . The occurrence of this surface disorder depends on the packing density, and for Cu, it is most pronounced on open surfaces (e. g., Cu (110)) but less likely for a close‐packed surface (e. g., Cu (111)) . The characteristic temperature for the onset of Cu (110) surface disorder was calculated to be about 80 °C below the bulk melting point, that is, surfaces with a correlation thickness larger than 4.3 Å would be expected from this theoretical modeling to be disordered at the graphene growth temperature of 1035 °C.…”

Surface reconstructions and premelting of the (100) CaF2surface

“…[9][10][11][12][13][14][15][16][17][18][19][20][21] Experimentally, the insulating behavior of alkaline halide surfaces hampers surface studies with electron probe beams and scanning tunneling microscopy. 22 Therefore, low-energy electron diffraction (LEED) 23,24 , X-ray diffraction 25 and atomic force microscopy (AFM) 26 are the experimental techniques well suited to study the structure of such surfaces. Beside such experimental techniques, computational and theoretical studies also have provided accurate results for such surfaces.…”