Nanotechnologies to enable high-performance superconductors for energy applications

High-temperature superconductors wires or coated conductors hold promise to revolutionize the transmission of electricity enabling the present electric grid to meet the world's growing energy needs. Although superconducting wires can carry 150 times more power than copper wires of the same cross section, further performance improvements are necessary for the superconducting technology to become cost-competitive. This objective can be achieved by introducing and controlling nanosized defects and nonsuperconducting phases within the superconducting film's matrix. Such nanostructures, when carefully engineered, significantly increase the loss-free current sustained by the superconductor through a mechanism known as flux pinning. This chapter is a review of the various types of nanostructures that are artificially introduced in superconducting films to enhance the superconductor's performance. Different approaches, materials, and techniques are discussed and the most recent results in this field compared. The last section of this chapter discusses an additional example of nanotechnology employment in superconducting wires. This nanotechnology can be regarded as an atomic surface treatment designed to enable the right crystallographic orientation of the superconducting film deposited on the metal template.