The molecular dynamics simulation method has been used to study the size- and shape-dependent lattice parameter of unsupported small Pt nanoparticles, where the shapes concerned are sphere, cube, and cuboctahedron. It is shown that the lattice parameters decrease with decreasing the particle size in specific shape. The lattice variations of cubic shapes are higher than those of cuboctahedral shapes, and those of cuboctahedral shapes are higher than spherical ones. Furthermore, the shape effect on lattice parameter increases with decreasing the particle size. By linear fitting the simulated results, it is found that the particle shape can contribute to 7% of the total lattice parameter variation for cubic shape and to 5% for cuboctahedral shape. The present simulation results are qualitatively consistent with experimental values and the predictions by Continuous-Medium (CM) model.
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This work was supported by Postdoctoral Science Foundation of Central South University, China Postdoctoral Science Foundation (no. 20070420185), and National Natural Science Foundation of China (no. 50401010).
Apai G, Hamilton JF, Stohr J (1979) Extended X-ray—absorption fine structure of small Cu and Ni clusters: binding-energy and bond-length changes with cluster size. Phys Rev Lett 43(2):165–169CrossRefADSGoogle Scholar
Cleri F, Rosato V (1993) Tight-binding potentials for transition metals and alloys. Phys Rev B 48(1):22–23CrossRefADSGoogle Scholar
Edelstein AS, Cammarata RC (1998) Nanomaterials: synthesis, properties and applications. Institute of Physics Publishing, Bristol, PhiladelphiaGoogle Scholar
Giorgio S, Henry CR, Chapon C et al (1990) Structure and morphology of small palladium particles (2–6 nm) supported on MgO micro-cubes. J Cryst Growth 100(1–2):254–260CrossRefADSGoogle Scholar
Goyhenex C, Henry CR, Urban J (1994) In-situ measurements of the lattice parameter of supported palladium clusters. Philos Mag A 69(6):1073–1084CrossRefADSGoogle Scholar
Heinemann K, Poppa H (1985) In-situ TEM evidence of lattice expansion of very small supported palladium particles. Surf Sci 156(1):265–274CrossRefADSGoogle Scholar
Kim HK, Huh SH, Park JW et al (2002) The cluster size dependence of thermal stabilities of both molybdenum and tungsten nanoclusters. Chem Phys Lett 354(1–2):165–172CrossRefADSGoogle Scholar
Kittel C (1996) Introduction to solid state physics, 7th edn. John Wiley & Sons, New YorkGoogle Scholar
Klimenkov M, Nepijko S, Kuhlenbeck H et al (1997) The structure of Pt-aggregates on a supported thin aluminum oxide film in comparison with unsupported alumina: a transmission electron microscopy study. Surf Sci 391(1–3):27–36CrossRefADSGoogle Scholar
Lamber R, Wetjen S, Jaeger NI (1995) Size dependence of the lattice parameter of small palladium particles. Phys Rev B 51(16):10968–10971CrossRefADSGoogle Scholar
Qi WH (2006) Study on size and shape effects of lattice parameter and cohesive energy of Pd nanoparticles. Acta Metall Sinica 42(10):1065–1070 (in Chinese)Google Scholar