High-temperature decomposition of solid solutions of beta-tantalum with copper in films

Research paper by Yu. Zh. Tuleushev, V. N. Volodin, E. A. Zhakanbaev

Indexed on: 04 Jun '14Published on: 04 Jun '14Published in: The Physics of Metals and Metallography


Using high-temperature X-ray diffractometry and electron microprobe analysis decomposition of alloys of beta-tantalum with copper produced by codeposition of sputtered ultradisperse particles of tantalum and copper has been established. At a temperature of 900°C, the precipitation of copper from the solid solution into an individual phase starts, and its diffusion onto the film surface with the formation of globular particles and simultaneous transition of the matrix β-modification into α-tantalum. The suggested mechanism of decomposition of solid solutions includes the following stages: the precipitation of copper into an individual phase, its diffusion onto the surface because of lattice pressure and the concentration gradient inside and outside the tantalum matrix, the coalescence of nanosized formations into drops at the coating surface, and the subsequent evaporation of copper from them in a vacuum.