Chapter 187 High-temperature superconductivity in layered cuprates: Overview

Abstract

This chapter highlights high-temperature superconductivity in layered cuprates. Although several other types of exotic superconductors (for example, organic superconductors, heavy-fermion f-electron superconductors, magnetically ordered superconductors, multinary rare-earth, actinide, and transition-metal superconductors) have been investigated intensely, the cuprate superconductors have received by far the most attention because the highest values of the superconducting critical temperature are found in this class of materials. Rare-earth and actinide elements are key constituents of many of the high-temperature cuprate superconductors and have played a prominent role in the development of the first and some of the more important cuprate superconductors. The high- T C cuprate superconductors have layered perovskite-like crystal structures that consist of conducting CuO 2 planes separated by layers comprised of other elements A and oxygen, A m O n , and, in some cases, layers of Ln ions. The mobile charge carriers that can be electrons but are usually holes, are generally believed to reside primarily within the CuO 2 planes. The A m O n layers apparently function as charge reservoirs that control the doping of the CuO 2 planes with charge carriers and as spacers that govern the anisotropy of the physical properties of the materials.