Abstract

Nonaqueous ytterbium, praseodymium, and erbium colloids and fine powders were prepared by cocondensation of the metals with 2-propanol and 2-butanone at 77 K. Films were formed from a mixture of the metals and metal oxides, and contained a certain amount of solvent. The powder X-ray diffraction patterns correspond to the respective lanthanide oxides. A complete characterization study by infrared spectroscopy was carried out to determine the presence of solvent in the amorphous films. The stability of the colloids and amorphous films at room temperature was measured. In addition, their stability in the presence of water moisture and oxygen was studied. Thermogravimetric studies showed that the films were stable up to 250°C, and the remnant solvent incorporated into them was degraded by 500°C. TGA-FTIR results indicate a self-catalysis process in which 2-propanol is oxidized by Yb, Er, and Pr to form carbonyl compounds. The morphologies of the films were studied by scanning electron microscopy. The shape and surface characteristics observed depended on the metal surface (copper or aluminum) used.