Title :
Sound propagation in disordered metals at low temperatures
Author :
Coppersmith, S.N.
Author_Institution :
AT&T Bell Lab., Murray Hill, NJ, USA
Abstract :
The acoustic properties of disordered materials below 1 K differ from those of perfect crystals because of the presence of two-level systems (TLSs) which contribute to ultrasonic attenuation. Conduction electrons cause the dynamics of TLSs in metals to be fundamentally different from that of TLSs in insulators. The author discusses how the interaction between TLSs and conduction electrons affects the dynamics of the TLSs in metallic glasses and in turn the acoustic properties of these materials. The theoretical calculations are compared to measurements of the sound attenuation and velocity in Pd0.775Si0.165Cu0.06 and Pd30Zr70
Keywords :
copper alloys; metallic glasses; palladium alloys; silicon alloys; ultrasonic absorption; ultrasonic propagation; ultrasonic relaxation; ultrasonic velocity; zirconium alloys; Pd0.775Si0.165Cu0.06; Pd30Zr70; acoustic properties; conduction electrons; disordered metals; low temperatures; metallic glasses; relaxational attenuation; sound propagation; sound velocity; tunnelling excitations; two-level systems; ultrasonic attenuation; Acoustic materials; Acoustic propagation; Attenuation; Conducting materials; Crystalline materials; Crystals; Electrons; Insulation; Metal-insulator structures; Temperature;
Conference_Titel :
Ultrasonics Symposium, 1992. Proceedings., IEEE 1992
Conference_Location :
Tucson, AZ
Print_ISBN :
0-7803-0562-0
DOI :
10.1109/ULTSYM.1992.275841
