Coherent Excitation of Acoustic Breathing Modes in Bimetallic Core-Shell Nanoparticles

JOSE H. HODAK; ARNIM HENGLEIN; GREGORY V. HARTLAND

JOURNAL OF PHYSICAL CHEMISTRY B

Año: 2000 vol. 104 p. 5053 - 5055

1089-5647

The low-frequency acoustic breathing modes in Au-Pb core-shell nanoparticles have been studied by timeresolvedspectroscopy. The frequency of the breathing mode was determined for a series of samples with a47 nm diameter Au core and Pb shells of different thickness. The measured frequencies decrease with increasingPb content, but not to the extent expected from a classical model for a homogeneous sphere. These resultsshow that the acoustic breathing modes of metallic core-shell particles are significantly perturbed when thetwo metals have different elastic properties.