HRTEM STUDIES OF THE EPITAXIAL-GROWTH OF PD PARTICLES (1-6 NM) ON ZNOMICROPRISMS

Pd particles (1 - 6 nm) were grown under UHV conditions from a Knudsen cell, on small ZnO prisms in situ prepared in a controlled atmosphere . 3-D Pd particles epitaxially oriented on the ZnO faces were observed by HRTEM, both in top view and in profile view on the lateral (10.0) faces of the ZnO prisms. The epitaxial relations were determined: (211 )(Pd) parallel to (10.0)(ZnO) and [0.11](Pd) parallel to [001](ZnO). F rom the HRTEM observations of the single ZnO prisms and the tetrapods twins, the precise structure of the central ZnO nucleus was also evide nced.