Size- and temperature-dependent structural transitions in gold nanoparticles.
Size- and temperature-dependent structural transitions in gold nanoparticles were revealed with morphology statistics obtained by high-resolution electron microscopic observations for thousands of particles annealed in a helium heat bath. We found that gold nanoparticles over a wide size range, 3-14 nm, undergo a structural transformation from icosahedral to decahedral morphology just below the melting points. It was also clarified that the formation of bulk crystalline structures from the decahedral morphology requires the melt-freeze process due to an insurmountable high free-energy barrier.
Koga
Kenji
K
Nanotechnology Research Institute, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan. k.koga@aist.go.jp
Ikeshoji
Tamio
T
Sugawara
Ko-ichi
K