Contact-free determination of the current–voltage law parameters for melt-textured YBCO superconductors in orthogonal magnetic field

A contact-free method to obtain the current–voltage characteristics (CVC) of hard superconductors by measuring the relaxation of the magnetization in a perpendicular magnetic field is developed. The relaxation curves obtained for melt-textured YBCO samples are well fitted by curves calculated within the electrodynamic model using a power-law CVC. This procedure uses only two fitting parameters, namely, the critical sheet current Jc and the exponent m of the power-law CVC.