Scanning tunneling microscopy of equilibrium crystal shape of Pb particles: test of universality

• Published in: Surface science Vol. 417; no. 2; pp. L160 - L165
• Main Authors: Arenhold, K., Surnev, S., Coenen, P., Bonzel, H.P., Wynblatt, P.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 20.11.1998; Amsterdam Elsevier Science; New York, NY
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Crystalline state; Crystalline state (including molecular motions in solids); Equilibrium thermodynamics; Exact sciences and technology; Faceting; Metals. Metallurgy; Morphology; Physics; Scanning tunneling microscopy; Structure of solids and liquids; crystallography; Surface energy; Vicinal single crystal surfaces; Scanning tunneling microscopy; Vicinal single crystal surfaces; Equilibrium thermodynamics; Morphology; Surface energy; Faceting; Universality class; Theoretical study; Lead; Crystal form; Metal particle; STM
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(98)00738-9

Small Pb crystallites equilibrated on Cu(111) and Ru(001) substrates were imaged by scanning tunneling microscopy. The curved crystal shape near a Pb(111) facet was analyzed in detail to determine the critical exponent. The results show that the exponent varies with azimuthal angle between 1.4 and 1.7. Both this variation and the shape of the (111) facet exhibit a threefold symmetry. The lower exponent of 1.4 corresponds to the directions with B-steps, characterized by (111)-type ledges. The higher exponent of 1.7, corresponding to A-steps, suggests long-range interactions between these steps. Thus, the transition of facet to curved surface near (111) does not exhibit a universal shape, in the sense of the Pokrovsky–Talapov universality class.