We report studies of bimetallic nanoparticles with 15%-16% atomic crystal parameters size mismatch. The degree of alloying was probed in a 2-nm Pt core (smallest attainable core size) of Pt-Ag nanoparticles (completely immiscible in bulk) and 20-nm-diameter Pd-Ag nanowires (completely miscible in bulk). Particles were synthesized radiolytically, and depending on the initial parameters, they assume spherical or cylindrical (nanowire) morphologies. In all cases, the metals are seen to follow their bulk alloying characteristics. Pt and Ag segregate in both spherical and wire forms, which indicates that strain due to crystallographic mismatch overcomes the excess surface free energy in the small particles. The Pd-Ag nanowires alloy similar to previously reported spherical Pd-Ag particles of similar diameter and composition.
F. D. Blum et al., "Bimetallic Pt-Ag and Pd-Ag Nanoparticles," Journal of Applied Physics, American Institute of Physics (AIP), Apr 2005.
The definitive version is available at http://dx.doi.org/10.1063/1.1888043
Mining and Nuclear Engineering
United States. Department of Energy
Keywords and Phrases
Bimetallic; Pt-Ag and Pd-Ag Nanoparticles; Crystallographic Mismatch
Article - Journal
© 2005 American Institute of Physics (AIP), All rights reserved.