Rheed study of Pd particle growth on α-alumina and NaCl substrates

Three-dimensional Pd particles were prepared by heteroepitaxial growth on NaCl (001) and alpha-Al2O3 (0001) substrates. During the deposition the particle structure and orientation were characterized by reflection high energy electron diffraction. It was shown that the particle epitaxial planes conserved the substrate surface symmetry - hexagonal or cubic. A CCD camera and a computer data treatment system were used for precise investigation of lattice parameter variation given by the particle interaction with the substrates. It was found that generally the lattice parameter parallel to the substrate remained constant due to the particle accommodation to the substrate while the perpendicular lattice parameter varied with particle size. Particle size was investigated by transmission electron microscopy.