Structure and Property of Single Crystalline MgO Films Embedded Fine Metal Crystallites

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During the term of the research, composite films of metal-magnesium oxide are studied, Au, Pu, Pb, Fe, Cr and Ti being chosen as metal and also Ge and PbS as semiconductor. In most metals, metal is embedded homogeneously inside single crystalline magnesium oxide in the form of fine metal crystallites of a few nm in size with theepitaxial orientation. For Ti, fine TiO crystallites of less than 1 nm in size are grown epitaxially inside magnesium oxide film. For Ge, amorphous Ge fine particles are grown. These specimens are characterized by high resolution electron microscopy and the following resuts are obtained : (1) the thickness of metal crystallites are estimated to be a few atomic layers ,(2) the strain analysis of the periphery of Fe particles arised from the accomodation with the magnesium oxide lattice is carried out and (3) the observation of atomic clusters as well as isolated single atoms are carried out by using the off-Bragg condition.Recently, the electric resistance and the magnetization of these composite films are measured to clarify the physical properties. The negative temperature coefficients of the resistivity in the temperature region of -150゜C to 250゜C for MgO-Au and MgO-Pd composite films and the behavior can be explained in terms of "activation-tunnelling model" The magnetization for extremely low temperature is measured with SQUID for MgO-Fe composite films and the formation of the spin glass is confirmed.