Fig. 4.19. Multilayer deposition of Pt (5 nm)
nanocrystals on a polycrystalline Au substrate.
After each deposition, the structure was
characterized by STM, X-ray diffraction and
XPS. (a) STM image obtained after the second
deposition showing the presence of regular
arrays of nanoparticles with an interparticle
spacing of 2 nm, extending over 300 nm,
corresponding to the size of a typical flat
terrace on the substrate. (b) X-ray diffraction
pattern of the arrays after the first, third and
fifth depositions exhibiting a low-angle
reflection with the d-spacings reflecting the
particle diameter and the interparticle distance.
(c) X-ray photoelectron spectra in the Pt(4f )
and Au(4f ) regions for the 5 nm Pt/Au system.
The intensity of the Pt(4f ) feature increases
with the number of depositions, accompanied
by a decreases in the Au(4f ) intensity as the
substrate gets increasingly shadowed due to
the limited escape depth of the photoelectrons.
4 Mesoscopic Assembly and Other Properties of Metal and Semiconductor Nanocrystals
74
nanocrystals on a polycrystalline Au substrate.
After each deposition, the structure was
characterized by STM, X-ray diffraction and
XPS. (a) STM image obtained after the second
deposition showing the presence of regular
arrays of nanoparticles with an interparticle
spacing of 2 nm, extending over 300 nm,
corresponding to the size of a typical flat
terrace on the substrate. (b) X-ray diffraction
pattern of the arrays after the first, third and
fifth depositions exhibiting a low-angle
reflection with the d-spacings reflecting the
particle diameter and the interparticle distance.
(c) X-ray photoelectron spectra in the Pt(4f )
and Au(4f ) regions for the 5 nm Pt/Au system.
The intensity of the Pt(4f ) feature increases
with the number of depositions, accompanied
by a decreases in the Au(4f ) intensity as the
substrate gets increasingly shadowed due to
the limited escape depth of the photoelectrons.
4 Mesoscopic Assembly and Other Properties of Metal and Semiconductor Nanocrystals
74