Angular variation of pinning near the irreversibility temperature in single crystals YBaCuO with splayed columnar defects”

J. A. HERBSOMMERA, *, J. LUZURIAGAA, L. CIVALEA, G. NIEVAA, G. PASQUINIB, H. LANZAB AND P. LEVYB

PHYSICA C - SUPERCONDUTIVITY

ELSEVIER SCIENCE BV

Lugar: New York; Año: 1998 vol. 304 p. 112 - 118

0921-4534

Angular variation of pinning near the irreversibility temperature in single crystals YBaCuO with splayed columnar defects” Abstract We have studied vortex pinning through ac susceptibility measurements in single crystals of YBCO with columnar defects (CDs). The CDs have 0°, 10° and 20° splay angle and average direction 10° off the c-axis. By studying the angular variation we can compensate for the anisotropy and effects of twins, etc. Using a simple expression we can obtain the angular spread when the field direction is outside the splay angle. An increase of pinning when the field direction is inside the angle defined by the CDs can be attributed to vortex entanglement due to the splay and the suppression of the sliding of double kinks. Author Keywords: Flux pinning; Pinning force; Critical current density; Columnar defects