Anomalous elastic behaviour of Bi-Pb-Ag composites

✍ Scribed by R.Ravinder Reddy; M. Muralidhar; V.Hari Babu; P.Venugopal Reddy

• Book ID: 103949043
• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 334 KB
• Volume: 220
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(94)90925-3

✦ Synopsis

Bi-Pb and Bi-Pb-Ag superconducting composites have been prepared by the solid state reaction method. After the usual characterization, ultrasonic longitudinal velocity and attenuation studies have been undertaken over a temperature range 80-300 K by the pulse transmission technique. In contrast to normal solids, the ultrasonic velocities of both the samples in the temperature range 200-100 K are found to decrease with decreasing temperature (softening), followed by a velocity maximum. The samples arc also found to exhibit longitudinal attenuation peaks at temperatures = 260, 160 and 120 K. An attempt has also been made to verify whether the Wachtman's equations can theoretically explain the low-temperature behaviour of the Young's modulus of these materials. A qualitative explanation for both the phenomena of softening of velocity as well as the occurrence of attenuation peaks is given.