Mechanical properties of filled antimonide skutterudites

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Vol. 170; no. 1; pp. 26 - 31
• Main Authors: Zhang, L., Rogl, G., Grytsiv, A., Puchegger, S., Koppensteiner, J., Spieckermann, F., Kabelka, H., Reinecker, M., Rogl, P., Schranz, W., Zehetbauer, M., Carpenter, M.A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.06.2010
• Subjects: Debye temperature; Density; Diamond pyramid hardness; Elastic constants; Elastic moduli; Grain size; Mechanical properties; Modulus of elasticity; Nanomaterials; Skutterudite; Sound velocity; Thermal expansion; Thermoelectricity; Mechanical properties; Elastic moduli; Skutterudite; Nanomaterials; Thermoelectricity
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/j.mseb.2010.02.022

Time-of-flight and resonant ultrasound spectroscopy techniques were employed for elastic moduli measurements on a set of various Fe 4Sb 12- and Co 4Sb 12-based skutterudites filled by mischmetal, didymium, or alkaline earths (Ca, Sr, Ba). A weak temperature influence on the longitudinal modulus C 11 indicates weak degradation of elastic properties within the thermoelectric working temperature range. Elastic moduli for Co 4Sb 12-based skutterudites are only slightly higher than for Fe 4Sb 12-based skutterudites, and the influence of various filler atoms or filling fractions on the elastic moduli is even smaller. Ball milled and hot pressed samples (grain size ∼250 nm) illustrate an obvious improvement of elastic properties in relation to those hot pressed from hand milled powders (grain size ∼50 μm). Debye temperatures calculated from sound velocity measurements are comparable to the values obtained from the parameters fitted to thermal expansion, which indicate that Co 4Sb 12-based skutterudites having slightly higher values than Fe 4Sb 12-based skutterudites. Vickers hardness is increased by Co or Ni substitution and demonstrates a linear dependence on density, Young's modulus, and shear modulus.