Tilt angle effect of intrinsic flux pinning in a single crystal of La1.85Sr0.15CuO4

✍ Scribed by T. Fukase; M. Kamata; K. Ishizuka; T. Suzuki; T. Goto; T. Sasaki

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 229 KB
• Volume: 263
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(95)00821-7

✦ Synopsis

The anisotropy of the activation energy of the flux pinning in a LaL85Sr0.~sCuO 4 single crystal was investigated by ultrasonic measurements in various directions of wave vector k, polarization vector u and magnetic fields H. The large activation energy of U(0 K, 14 T) = 972 K and small field dependence ot H -°'3 were obtained for H II c-plane, when the flux motion is parallel to the c-axis where the intrinsic pinning mechanism due to the layered structure is effective. The elastic modulus of the flux-line lattice which moves parallel to the c-axis is proportional to H 2 cos 20, and the value of U rapidly decreases with increasing tilt angle 0 between H and the c-plane (U(O ffi 10 °) ~ 300 K, U(O = 30 °) ~ 75 K). These angular dependences of the elastic modulus and the activation energy can be explained on the basis of the intrinsic pinning mechanism and the three-dimensional stepwise flux-line structure.