Fabrication of a Superstructured One-Dimensional Alloy in a Thin Film Using Bis(dimethylglyoximato)metal(II)

Abstract

We have investigated the fabrication of a superstructured one-dimensional alloy using bis(dimethylglyoximato)metal(II) (M(dmg) 2 , M = Pd, Pt) with a vacuum evaporation technique. It was found that coevaporation of these metal complexes gave a thin film of their mixed crystal. The films were quite transparent showing a strong d z 2 -p z transition band in the visible region, of which the peak wavelength subsequently varied in proportion to the mixing ratio. These results suggested that a linear alloy chain was formed in the film of the mixed crystal. A perpendicular orientation of the alloy chain axis could be obtained by depositing the mixed crystal on a KBr-cleaved surface. These findings make it possible to fabricate a one-dimensional superlattice in which several metal components are artificially arranged in a linear chain as designed. Pt(dmg) 2 and Pd(dmg) 2 were alternatively deposited on a KBr-cleaved surface. Peak shifts of the d z 2 -p z transition bands showed that a heterojunction between the platinum and palladium complexes could be formed in a linear alloy chain. It was revealed that the unit metal-chain length in a one-dimensional alloy could be tuned by the control of the deposited film thickness.