Title :
Ultrasonic studies in YBa2Cu3O7 and gallium-doped YBa2Cu3O7
Author :
Wolanski, M. ; Savarino, G. ; Coyne, T. ; Trivisonno, J.
Author_Institution :
Dept. of Phys., John Carroll Univ., Cleveland, OH, USA
Abstract :
The temperature dependence of the ultrasonic velocity and attenuation was measured in pure YBa2Cu3O7 and in samples doped with Ga. Doping concentrations between 2 and 7 at.% were used. Both longitudinal waves and shear waves were studied for frequencies between 5 and 50 MHz. The results show that the low-temperature peak in the attenuation and the anomalous hardening which usually occurs near Tc in pure samples is not present in doped samples and therefore suggests that these features are not associated with the superconducting transition temperature. The results are compared with those of other ultrasonic studies and recent internal friction studies
Keywords :
barium compounds; gallium; high-temperature superconductors; ultrasonic absorption; ultrasonic velocity; yttrium compounds; 5 to 50 MHz; YBa2Cu3O7; YBa2Cu3O7:Ga; attenuation; high Tc superconductors; high temperature superconductors; internal friction; longitudinal waves; shear waves; superconducting transition temperature; temperature dependence; ultrasonic velocity; Acoustic measurements; Acoustic transducers; Attenuation measurement; Frequency; Hysteresis; Microstructure; Pulse measurements; Temperature dependence; Ultrasonic variables measurement; Yttrium barium copper oxide;
Conference_Titel :
Ultrasonics Symposium, 1989. Proceedings., IEEE 1989
Conference_Location :
Montreal, Que.
DOI :
10.1109/ULTSYM.1989.66942
