High temperature mechanical spectroscopy of CaO–ZrO2 cubic single crystals

✍ Scribed by L. Donzel; R. Schaller

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 470 KB
• Volume: 46
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/s1359-6454(98)00175-x

✦ Synopsis

AbstractÐThe high temperature anelastic properties of cubic CaO±ZrO 2 single crystals have been studied by mechanical spectroscopy. A relaxation peak superimposed on an exponential background has been observed at 1580 K for a frequency of 1 Hz. The mechanism giving rise to the peak is thermally activated, the activation energy is 4.3 eV and the limit relaxation time is about 4 Â 10 À15 s. The peak depends on the crystal orientation and the intensity of the relaxation follows a Curie±Weiss type law. These characteristics lead to the interpretation that this peak is the stress induced ordering of substitutional Ca±Ca pairs (orthorhombic h011i elastic dipoles). The deviations of the relaxation time from the Arrhenius behavior and of the relaxation intensity from the Curie±Weiss law observed below 1440 K might result from the order±disorder transition occurring in this temperature range. The exponential background may be attributed to dislocation motion. The apparent activation energy associated with this background was found to be 6.4 eV.