https://doi.org/10.1007/s100510070138
The microstructure of hydrogen- and deuterium-doped nanocrystalline palladium studied by small-angle neutron scattering
1
Institut für Festkörperphysik, Technische
Universität Darmstadt, Hochschulstraße 6, 64289 Darmstadt,
Germany
2
Paul Scherrer Institut, 5232 Villigen PSI,
Switzerland,
3
Materialwissenschaft, Technische Universität
Darmstadt, Petersenstraße 23,
64287 Darmstadt, Germany
4
Institut Laue Langevin, 6 rue Jules Horowitz, BP 156, 38042 Grenoble
Cedex 9, France
Received:
1
May
2000
Published online: 15 September 2000
By means of small-angle neutron scattering the
microstructure of two nanocrystalline Pd samples (prepared by
inert gas condensation) has been studied at room temperature in a
Q-range from 
to
. An additional subsequent
doping of the two samples with
H as well as with D (concentrations < 4 at% ) caused contrast
variations that provided more detailed structural information. The
measured scattering intensity was modeled by a Porod contribution
from large heterogenities (e.g. pores) and a contribution
from spherical grains with a log-normal distribution of their
radii. To account for the presence of grain boundaries, the grains
were considered to be surrounded by a shell with a reduced Pd
density and a thickness half as large as the thickness of the
grain boundaries. For the above model, the data of the H-doped,
D-doped and undoped sample were simultaneously fitted with one
single set of adjustable parameters. The fits yielded for the two
samples volume-weighted mean grain radii of 10 nm and 13 nm. The
values for the grain boundary thickness lie between 0.2 and 0.8 nm.
Almost all of the H- and D-atoms are, at low hydrogen
concentrations, located in the grain boundaries.
PACS: 61.46.+w – Clusters, nanoparticles, and nanocrystalline materials / 61.12.Ex – Neutron scattering techniques (including small-angle scattering) / 61.72.Mm – Grain and twin boundaries
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000
