Thickness-dependent formation of Gd-silicide compounds

• Published in: Journal of applied physics 1988-12, Vol.64 (12), p.6746-6749
• Main Authors: MOLNAR, G, GEROCS, I, PETO, G, ZSOLDOS, E, JAROLI, E, GYULAI, J
• Format: Article
• Language: English
• Subjects: Analysing. Testing. Standards; Applied sciences; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Measurement of properties and materials state; Metals, semimetals and alloys; Metals. Metallurgy; Nondestructive testing; Physics; Solid surfaces and solid-solid interfaces; Specific materials; Surface structure and topography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.342006

Gd-silicide phases were investigated by x-ray diffraction. The results showed that not only one phase exists in a Gd thin-film and silicon substrate reactions. The first phase formed was hexagonal GdSi≊1.7, the second orthorhombic GdSi2. The ratio of the two phases depends on temperature of the heat treatment, and at a given temperature and time of annealing, a dependence of the thickness of the evaporated Gd layer was found. At ∼100-nm Gd thickness the dominant phase was orthorhombic GdSi2, at ∼250 nm hexagonal GdSi≊1.7. In the 300–1000-nm interval orthorhombic GdSi2 was the main component again. Rutherford backscattering analysis showed that the phases were found mixed within the layer. This thickness-dependent formation could be described with a simple model proposed by Gösele and Tu [J. Appl. Phys. 53, 3252 (1982)].