Unexpected high stiffness of Ag and Au nanoparticles.
We studied the compressibility of silver (10 nm) and gold (30 nm) nanoparticles, n-Ag and n-Au, suspended in a methanol-ethanol mixture by x-ray diffraction (XRD) with synchrotron radiation at pressures up to 30 GPa. Unexpectedly for that size, the nanoparticles show a significantly higher stiffness than the corresponding bulk materials. The bulk modulus of n-Au, K(0)=290(8) GPa, shows an increase of ca. 60% and is in the order of W or Ir. The structural characterization of both kinds of nanoparticles by XRD and high-resolution electron microscopy identified polysynthetic domain twinning and lamellar defects as the main origin for the strong decrease in compressibility.
Gu
Q F
QF
Laboratory of Crystallography, Department of Materials, ETH Zurich, CH-8093 Zurich, Switzerland.
Krauss
G
G
Steurer
W
W
Gramm
F
F
Cervellino
A
A