Ultrasonic Measurement of the Elastic Moduli of Rutile

Four of the elastic moduli of rutile have been determined by measuring the velocity of 10-Mc ultrasonic waves. They are C11equals;2.48±0.08, C33=4.52±0.08, C44=1.20±0.03, and C56=1.6±0.1, all×1012 d/cm2. The remaining two, C12=2.0±0.1×1012 d/cm2 and C13=1.4±0.1×1012 d/cm2, were computed from the given data and Bridgman's compressibility data. These values are, with the exception of C33, in good agreement with values computed from force constant data. No change in elastic moduli was noted upon reduction to a resistivity of 0.2 ohm/cm. It was noted that attenuation was greater in reduced than in fully oxidized rutile and was considerably greater in the a than in the c crystallographic direction.