Field, temperature, and angle dependent critical current density J(c)(H, T, theta) in coated conductors obtained via contact-free methods

摘要

Applications of coated conductors based on high-T-c superconductors often require detailed knowledge of their critical current density J(c) as a function of magnetic field orientation as well as field strength and temperature. This work demonstrates experimental methods for obtaining the angularly dependent J(c) using contact-free magnetic measurements, and qualifies those methods using several well defined conditions. The studies complement traditional transport techniques and are readily extended to conditions of field and temperature where the current density is very large and transport methods become difficult. Results on representative materials are presented.