title: Crystal structure anisotropy explains anomalous elastic properties of nanorods.
abstract: It is demonstrated that the frequency of the extensional vibrational mode of a nanorod made of an elastically anisotropic crystalline material deviates widely from the predictions of the theories based on the analysis of the long-wavelength limit. The dispersion relation for the fundamental extensional mode of a gold rod grown in the [100] direction is calculated and found to be in excellent agreement with experimental data obtained from the transient optical absorption measurements on gold nanorods. This explains an anomaly in the elastic properties of nanorods which was previously attributed to a 26% decrease in Young's modulus for nanorods compared to its bulk value. The developed approach allows one to investigate the role of the crystal structure anisotropy for acoustic phonons in nanorods and nanowires made of any metal or semiconductor material having cubic crystal structure.
authors.affiliation: Department of Physics, Jackson State University , Jackson, Mississippi 39217, United States.
authors.forename: Serguei V
authors.initials: SV
authors.lastname: Goupalov