500 ACTA METALLURGICA, VOL. 10, 1962

Radiation effects in natural quartz. Phonon-phonon interaction changes and annealing out of defects*

In-reactor irradiation measurements on single crystal natural quartz have been interpreted in terms of ultrasonic attenuation and velocity. Dif- ferences in attenuation before and after such irradiation have also been made as a function of both ultrasonic

frequency (up to 1500 Mc/sec) and temperature (down to 1.5-2.O”K). Phonon-phonon interaction at 500 Mc/sec is described with particular regard to

--_____. .- l Abstract of Paper 3 presented at the Conference on Internal

Friction held on 10 and 11 July, 1961 at Cornell University.

changes brought about by irradiation. Such attenu- ation-frequency and attenuation-temperature measu-

rements are again made after most of the defects have been annealed out as shown by attenuation-tem- perature measurements made up to about 510°C. It is also shown that quartz can be taken well above the a-+? transition temperature at 575°C without destroying the piezoelectric behavior when the tem- perature is again lowered below the transition tem- perature.

Metals Research Laboratory . THOMAS FITZGERALD

Brown University, ROHN TRUELL

Providence, Rhode Island