Thermomechanical properties of amorphous hydrogenated carbon-germanium alloys

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2000-12, Vol.71 (6), p.633-637
• Main Authors: MARQUES, Ec, VILCARROMERO, J, LACERDA, R. G
• Format: Article
• Language: English
• Subjects: Alloys; Bonding strength; Carbon; Condensed matter: structure, mechanical and thermal properties; Crystal structure; Elasticity, elastic constants; Exact sciences and technology; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Physics; Stress concentration; Stresses; Thermal expansion; Thermal properties of amorphous solids and glasses: heat capacity, thermal expansion, etc; Thermal properties of condensed matter; Thermomechanical properties
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s003390000573

Thermomechanical properties of amorphous hydrogenated carbon-germanium alloys prepared by the rf sputtering technique were determined for films in the 0 at.% to 100 at.% carbon content range. The stress, thermal expansion coefficient, and elastic modulus were obtained using the thermally induced bending technique. The stress was related to the concentration of hydrogen and argon, to the difference in the Ge-Ge and Ge-C bond length, and to the carbon hybridization. The thermal expansion coefficients of pure amorphous germanium and amorphous carbon are higher than that of their corresponding crystalline counterparts, which was attributed to the compressive stress of the films. The biaxial modulus, on the other hand, are always smaller than that of their crystalline counterparts, but increases as the concentration of carbon increases due to the substitution of Ge-Ge bonds by energetically stronger Ge-C and C-C bonds.