TY - JOUR
T1 - Femtosecond electron diffraction
T2 - Preparation and characterization of (110)-oriented bismuth films
AU - Moriena, Gustavo
AU - Hada, Masaki
AU - Sciaini, Germn
AU - Matsuo, Jiro
AU - Dwayne Miller, R. J.
N1 - Funding Information:
This research was supported by the Natural Science and Engineering Research Council of Canada and the Canada Foundation for Innovation and partially supported by the Core Research for Evolutional Science and Technology (CREST) program of the Japan Science and Technology Agency (JST).
PY - 2012/2/15
Y1 - 2012/2/15
N2 - Here, we present a new approach to synthesize (110)-oriented ultrathin membranes of bismuth (Bi). This rather exotic orientation was achieved by directing the growth through rationale control of lattice matching. Bi films were hetero-epitaxially grown on the (100)-surface of freshly cleaved potassium chloride crystals. The sample orientation was characterized by x-ray and electron diffraction. In addition, high quality free-standing films were obtained after dissolution of the substrate in water and controlled evaporation. Femtosecond electron diffraction (FED) was, therefore, used to monitor the coherent shear acoustic phonons in (110)-oriented free-standing Bi films produced by impulsive femtosecond optical excitation. The small de Broglie wavelength (flat Ewald sphere) of keV-electrons combined with an off-Bragg detection scheme provided a magnified view of shear atomic motions, i.e., lattice distortions in the transverse direction. All-optical pump-probe experiments are usually insensitive to shear displacements, a fact that makes FED a unique non-contact method to achieve the complete characterization of elastic properties of nanoscale materials.
AB - Here, we present a new approach to synthesize (110)-oriented ultrathin membranes of bismuth (Bi). This rather exotic orientation was achieved by directing the growth through rationale control of lattice matching. Bi films were hetero-epitaxially grown on the (100)-surface of freshly cleaved potassium chloride crystals. The sample orientation was characterized by x-ray and electron diffraction. In addition, high quality free-standing films were obtained after dissolution of the substrate in water and controlled evaporation. Femtosecond electron diffraction (FED) was, therefore, used to monitor the coherent shear acoustic phonons in (110)-oriented free-standing Bi films produced by impulsive femtosecond optical excitation. The small de Broglie wavelength (flat Ewald sphere) of keV-electrons combined with an off-Bragg detection scheme provided a magnified view of shear atomic motions, i.e., lattice distortions in the transverse direction. All-optical pump-probe experiments are usually insensitive to shear displacements, a fact that makes FED a unique non-contact method to achieve the complete characterization of elastic properties of nanoscale materials.
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U2 - 10.1063/1.3684975
DO - 10.1063/1.3684975
M3 - Article
AN - SCOPUS:84857854665
SN - 0021-8979
VL - 111
JO - Journal of Applied Physics
JF - Journal of Applied Physics
IS - 4
M1 - 043504
ER -