Ultrasonic investigation of thermally assisted flux flow in (La1−xSrx)2CuO4 ceramics

✍ Scribed by Yuuji Horie; Takayoshi Miyazaki; Takeshi Fukami

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 825 KB
• Volume: 175
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(91)90239-u

✦ Synopsis

We measured the change in the ultrasonic attenuation coefilcient A(Y ( r, H) and sound velocity A V,( r, H) with temperature T and magnetic field H for (La_,Sr,),CuO, (x=0.075) ceramic samples. While both Aa and AV,(H).varied ccH"(n-1.6) at a temperature T~4.2 K, no difference was observed in the AV,(H) versus H curves between the cases of HllK and HIK (K: polarization vector of sound waves), and the theory of Pankert. Furthermore, the plots of (Y ( r, 10 T ) -a( r, 0 T ) versus Tshowed a broad peak at T-30 K accompanied by a broad step in the V,( r, 10 T) -V,( 7', 0 T) versus Tcurve. Although the peak could be attributed to energy dissipation due to thermally assisted flux flow, the width of the peak was much larger than the prediction of the theory. Here, we adopted the intrinsic pinning model proposed by Tachiki et al. for the explanation of the discrepancies with the theory.