Au-Cu bimetallic colloids prepared by cocondensation with nonaqueous solvents

Au-Cu colloids were prepared by chemical liquid deposition (CLD). The metal s were evaporated simultaneously to yield atoms, which were solvated to yie ld bimetal atom mixtures at 77 K, and upon warming, in some cases, stable l iquid colloids were formed with a narrow range of particle size. The solven ts under study were acetone, 2-butanone, 2-propanol, 2-methoxyethanol, 2-et hoxyethanol, diglyme, THF, and DMF. The particle size of the bimetallic col loids ranged from 21 to 48 Angstrom. The films or powders were prepared by direct evaporation of the solvents from bimetallic colloids. Microanalysis demonstrated that these films contained carbon and hydrogen residues. Infra red spectra showed that hydrocarbon residues were present in the films. The rmal studies demonstrated the low stability of the Au-Cu films. Two or thre e decomposition temperatures were observed in the thermograms. In most of t he films, a total weight loss of 10-15%, at 550 degrees C, was registered. (C) 2000 Elsevier Science Ltd.