HIGH-RESOLUTION ELECTRON-MICROSCOPY OF COMPOSITE FILMS OF GOLD AND MAGNESIUM-OXIDE

Composite films of gold crystallites embedded in magnesium oxide (001) and (110) single crystalline films are prepared by the simultaneous vacuum deposition technique for the study of metal-magnesium oxide composite films. The epitaxially grown gold crystallites of a new nm in size are analysed from the contrast of the lattice images by using computer-simulated images. The lattice fringes at the crystallites are observed with two kinds of spacing of gold or magnesium oxide depending on the defocus condition, which suggests that the thickness is a few atomic layers. The result is also inferred from the growth condition in the simultaneous deposition. The fact that no strain contrast is apparent shows that gold crystallites grow almost coherently inside the magnesium oxide. The imaging characteristics of the composite films are studied in detail on the thickness and the depth of the gold crystallites.