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T. Götsch, M. Stöger-Pollach, R. Thalinger, S. Penner:
"The Nanoscale Kirkendall Effect in Pd-Based Intermetallic Phases";
The Journal of Physical Chemistry C, 118 (2014), 17810 - 17818.

Hollow particles of Pd−X intermetallic phases (X = Ga, Ge, Sn) are
prepared by reduction of the respective oxide-supported Pd/XO2 and Pd/X2O3 thin films
via the nanoscale Kirkendall effect. Void formation and stability was investigated by
(scanning) high-resolution transmission electron microscopy and spectroscopy. Analysis of
the selected area electron diffraction patterns after different reductive steps revealed a
direct correlation of void size and stability with the composition of the respective
intermetallic compounds. Voids only appear for Pd-rich Pd2X phases, whereas for
intermetallic compounds of lower Pd content, PdX, the particles are solid again. Energyfiltered
electron microscopic images show that the voids are indeed empty and formed by
faster Pd outward diffusion compared to X inward diffusion.

http://dx.doi.org/10.1021/jp505458v