The Molecular Precursor Method, MPM, is one of the wet processes for the thin film fabrication of various metal oxides or phosphate compounds. This method pertinent to the coordination chemisty and materials science including nanoscience and nanotechnology, has been developed by our laboratory in Kogakuin University.

The MPM is based on the design of metal complexes in coating solutions with excellent stability, homogeneity, miscibility, coatability, etc., which are practical advantages. This method is related to the fact that metal complex anions with high stability can be dissolved into volatile solvents such as ethanol by combining them with appropriate alkylamines. Furthermore, the resultant solutions can form excellent precursor films by using various coating procedures. The precursor films involving metal complexes should be amorphous, just as with the metal/organic polymers in the sol-gel processes; otherwise, it would not be possible to obtain the resulting metal-oxide thin films spread homogeneously on substrates by heat treatment. For this purpose, the alkyl groups in the used amines play an important role. The used amine sometimes links to the central metal ion in the coating solution, when the central metal ion of the complex is a hard acid.

(Photo)
The spinel-type Co3O4 thin film of 100 nm thickness on a sola lime glass. The brown-colored material coated with the Co3O4 thin film can be applied to an evacuated heat collector. (See; Sato et. al., Solar Energy Materials and Solar Cells (1997), 45, 43-49)

12 Jan., 2012