Vortex bending in a tilted crystal

Magnetization-vector measurements were made on a (Formula presented) crystal, initially cooled to 4.2 K in an external field (Formula presented) parallel to the (Formula presented) axis. With (Formula presented) fixed, the crystal was then tilted, such that the angle θ between the (Formula presented) axis and (Formula presented) was gradually raised to 90° and lowered back to zero. Our results reveal that all the vortex flux remains parallel to the (Formula presented) axis until the tilt angle θ reaches a threshold value (close to 15° for (Formula presented) As θ exceeds this value, the vortex flux in the (Formula presented) plane rises rapidly from zero, and it appears to derive solely from a bending of the vortices initially directed along (Formula presented) This whole process is fairly consistent with theoretical predictions, and it is found to be essentially reversible with the cycling of θ at low (Formula presented) The hysteresis that develops at higher (Formula presented) rises and approaches the conventional hysteresis measured along (Formula presented) after zero-field cooling. Comparison is also made with a cross-flux experiment, which is seen to be only superficially equivalent to the crystal-tilt experiment.