Step patterns on vicinal reconstructed surfaces

Vilfan, I.

doi:10.1016/0039-6028(95)01074-2

Cited by 12 publications

(10 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The step pattern appearing in Figure 4 is typical for the h-BN/Pt(110) system and indicates a dramatic change in the reconstructed Pt(110), this ratio exceeds one order of magnitude, 24 and the large anisotropy gives rise to the socalled fish-scale pattern on slightly miscut Pt(110) crystals. 25,26 After being covered by the h-BN layer, steps in both orthogonal directions appear to be almost equivalent in energy; however, steps running along the [11̅ 0] direction occasionally pair up underneath the h-BN film, thus forming double steps of 277 pm height, as seen in Figure S1.…”

Section: Resultsmentioning

confidence: 96%

Quasiliquid Layer Promotes Hexagonal Boron Nitride (h-BN) Single-Domain Growth: h-BN on Pt(110)

2019

View full text Add to dashboard Cite

Hexagonal boron nitride (h-BN) monolayers were grown on Pt(110) using borazine as a precursor molecule. The resulting surface structure was studied by scanning tunneling microscopy, low-energy electron diffraction, and density functional theory calculations. Borazine fragments reduce the roughening temperature of pristine Pt(110) (T r = 1090 K); consequently, growth below T = 1100 K results in a serrated h-BN/Pt(110) surface with small terraces, defects, and domain boundaries. Surprisingly, h-BN deposition at T > 1100 K yields large terraces covered by a carpet-like single-domain h-BN monolayer. Despite the incommensurability and different symmetry, the epitaxial growth is almost perfect. The key to this counterintuitive behavior is the "soft" Pt(110) surface responding to the h-BN overlayer in two ways: First, the (1 × 2)missing-row (m.r.) reconstruction is converted into a (1 × n)-m.r. reconstruction with a regular alternation of n = 5 and 6, yielding a superperiodicity of the Moirépattern. Second, the remaining rows experience significant relaxations. Some Pt surface atoms are mobile underneath the h-BN monolayer, even at room temperature. Under growth conditions, the top metal layer is disordered and highly mobile, rendering the h-BN growth comparable to that on liquid gold. Such a mechanism may be of general relevance for the epitaxial growth of 2D materials. Because epitaxial deposition of Pt(110) on various substrates has been demonstrated, the present system appears scalable, and its regular 1D grooves render it a promising template for nanowire arrays.

show abstract

Section: Resultsmentioning

confidence: 96%

Quasiliquid Layer Promotes Hexagonal Boron Nitride (h-BN) Single-Domain Growth: h-BN on Pt(110)

2019

View full text Add to dashboard Cite

show abstract

“…With the appropriate shear modulus 1 2 ͑C 11 -C 12 ͒ and assuming an island length of the order of 10 000 Å one obtains 220 , s xx , 400 meV Å 22 for ͕110͖ step energies [18,24] 30 ,´, 100 meV Å 21 . This is in qualitative agreement with s xx 317 meV Å 22 as calculated by Feibelman [25].…”

mentioning

confidence: 99%

“…The elastic constants C ij of the substrate are taken from experimental values as cited by Mehl and Papaconstantopoulos [23]. The step formation energy´s of the ͕001͖ steps has been determined [12,24] as 2.3 meV Å 21 . Interestingly,´s can also be obtained from the step intersection angle a in areas with sufficiently low step density to exclude elastic step-step interactions [24].…”

mentioning

confidence: 99%

“…The step formation energy´s of the ͕001͖ steps has been determined [12,24] as 2.3 meV Å 21 . Interestingly,´s can also be obtained from the step intersection angle a in areas with sufficiently low step density to exclude elastic step-step interactions [24]. From our STM data we obtain a 16 ± and consequently´s 2.45 meV Å 21 , if we assume that the step angle equilibrates at room temperature.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Mesoscopic Self-Organization Induced by Intrinsic Surface Stress on Pt(110)

Hanesch

Bertel

1997

Phys. Rev. Lett.

View full text Add to dashboard Cite

Scanning tunneling microscopy revealed a quasi-one-dimensional periodic island structure on the clean Pt(110)-͑1 3 2͒ surface. The period is about 1500 Å. As indicated by several test experiments, the structure corresponds to the thermodynamic equilibrium. This spontaneous island formation is attributed to mesoscopic self-organization induced by the intrinsic surface stress. It is demonstrated that such mesoscopic structures allow determination of the absolute surface stress. The present result agrees with ab initio calculations. [S0031-9007(97)

show abstract

“…In a recent paper Vilfan [9] discussed the influence of long range interactions, which become important for a higher density of steps. However, he does not take into account the instabilities arising from the quadratic terms in the expressions for the surface free energy.…”

mentioning

confidence: 99%

Networks of Steps on Crystal Surfaces

Carlon

Beijeren

1996

Phys. Rev. Lett.

View full text Add to dashboard Cite

Scanning tunneling microscopy observations show that steps on vicinal surfaces near (110) missingrow reconstructed surfaces of metals such as Au and Pt tend to form networks. A simple microscopic model introduced here shows that these networks are unstable (or metastable) against faceting. This leads to the formation of ridges between rounded areas and of angles in the equilibrium shape of the (110) The free energy per unit of area of a crystal surface depends rather strongly on the surface orientation. Typically, especially at low temperatures, certain orientations corresponding to high symmetry directions in the crystal lattice have low free energies and appear as large flat areas (facets) in the equilibrium crystal shape (ECS).Orientations tilted over a small angle with respect to a facet are called vicinals and consist of steps separated by large terraces. The free energy of a vicinal is typically expressed as an expansion in the step density p ͑p ø 1͒.In this Letter we investigate the surface free energies of certain vicinals of missing-row (MR) reconstructed ͑110͒ facets of metals such as Au and Pt. We will show that these orientations are, in fact, not stable which leads to faceting, or in other words to the presence of sharp edges in the ECS [1]. Figure 1 shows a typical pattern of steps found on vicinal orientations of Au and Pt͑110͒ surfaces [2,3] (areas of equal contrast denote terraces of the same height). Instead of an array of parallel steps, as found ordinarily on such surfaces, one sees a pattern of zigzagging steps, which repeatedly touch each other at a collection of contact points. We call this pattern a network of steps, since we can think of it as two arrays of roughly parallel steps, making on average angles f and 2f, with the vertical direction in Fig. 1.Why is the surface forming this pattern? The explanation [3] is related to the large energy difference between two different types of steps which can be generated on the surface: the clockwise (CW) steps and the anticlockwise (ACW) steps, illustrated in the examples of Fig. 2. Scanning tunneling microscopy (STM) observations at room temperature show that ACW steps appear very rarely on the surface and CW steps, which cost lower energy, prevail [2,3]. In Fig. 2(a) we show two possibilities for the microscopic configurations of steps: on the left side the typical crossing pattern as observed in STM experiments; on the right side two pieces of isolated steps, coming close to each other in the given example. Figure 2(b) shows the cross section of the surface along the segment AB: going from A to B one meets a CW up step and a CW down step, with a change in the reconstruction state as shown in the figure. In the configuration on the right side of Fig. 2(a), the points C and D belong to the same terrace, and therefore belong to the same reconstructed state. Only a combination of a CW and an ACW step matches this requirement [ Fig. 2(c)]. The situation where four terraces meet in a single point is favored, since only

show abstract

Step patterns on vicinal reconstructed surfaces

Cited by 12 publications

References 12 publications

Quasiliquid Layer Promotes Hexagonal Boron Nitride (h-BN) Single-Domain Growth: h-BN on Pt(110)

Quasiliquid Layer Promotes Hexagonal Boron Nitride (h-BN) Single-Domain Growth: h-BN on Pt(110)

Mesoscopic Self-Organization Induced by Intrinsic Surface Stress on Pt(110)

Networks of Steps on Crystal Surfaces

Contact Info

Product

Resources

About