Superconductors and Superconductivity

Abstract

High temperature superconductors (HTS) have the ability to carry high-density electrical currents with very little energy dissipation. This property makes high temperature superconducting wires extremely desirable for many areas of technology such as power generation and transmission, electric motors, magnetic levitation, and high magnetic field generation. Many HTS materials are brittle ceramics and cannot be used by themselves to make the wires required for these applications. Currently, coated conductors (CC) are the most promising method of manufacturing superconducting wires because they provide a flexible base for a thin layer of HTS, which circumvents the brittleness issue.

Nickel and nickel alloys are the most commonly used substrate materials because they are flexible and amiable to the thermomechanical processing of the wire making process. The ferromagnetic properties of these materials, however, cause energy to dissipate when a current flows in the CC. This research studies the ferromagnetic properties of two different nickel-tungsten alloys (NiW) that are used as substrates to study their effects (if any) on the critical current density (J_c) of YBCO, an HTS material, coated conductors. The study reveals that the energy dissipated by the ferromagnetic properties of the nickel-tungsten substrates have little to no effect on the critical current density. This justifies the use of nickel-tungsten substrates in application despite the small amount of energy loss.