Electron diffraction analysis of the decomposition of the metastable phase of amorphous bismuth with high hydrogen content
Abstract
An electron diffraction investigation of the coordination structure of amorphous bismuth films, obtained by deposition in a hydrogen atmosphere on a substrate cooled with liquid helium to temperatures ∼3.5 °K, was conducted. Primary attention was devoted to the study of the changes in the coordination structure of films accompanying the decomposition in the previously observed [Sov. J. Low Temp. Phys. 8, 272 (1982); Phys. Status Solidi B 114, 467 (1982)] metastable a-Bi (H) phase occuring at ∼5 °K. The diffraction data were processed on a computer for the purpose of constructing the radial distribution functions of the atomic density. It was found that with the decomposition of the a-Bi (H) phase, the average number of atoms in the first coordination sphere decreases considerably. The results obtained can serve as a basis for an explanation of the large changes in the resistivity and the temperature of the superconducting transition Tc accompanying the decomposition of the a-Bi (H) phase.