Ionic superconductor

Because of the high values of conductivity which in individual cases are found at room temperature, such compounds are often called superionic conductors or ionic superconductors but these designations are unfounded, and a more correct designation is solid ionic conductors. Strictly unipolar conduction is typical for all solid ionic conductors in the silver double salts, conduction is due to silver ion migration, whereas in the sodium polyaluminates, conduction is due to sodium ion migration. 

To be able to speak of ionic superconductors, and there is a certain haziness on this subject, we need at the same time a high concerrtration of mobile charges (= 1022/cm ) and a small value of Ug (thus stabilized zirconia is not an ionic superconductor). The residence time of an ion on its site is comparable to the hopping time and the simple model given here can no longer be applied. The lattice dynamics of the mobile ions is very complex. 

Breiter, M. W. Low-Temperature Electrochemistry at High-T2 Superconductor/Ionic Conductor Interfaces 28... 

All metals conduct electricity on account of the mobility of the electrons that bind the atoms together. Ionic, molecular, and network solids are typically electrical insulators or semiconductors (see Sections 3.f3 and 3.14), but there are notable exceptions, such as high-temperature superconductors, which are ionic or ceramic solids (see Box 5.2), and there is currently considerable interest in the electrical conductivity ol some organic polymers (see Box 19.1). 

Optimization of all of these categories of materials has produced solids in which the ionic conductivity is as large as that normally found in solutions (Fig. 6.1). Such materials are sometimes called super-ionic conductors, but the terms fast ion conductors or solid electrolytes are to be preferred to avoid confusion with metallic superconductors, which transport electrons and holes, not ions, and by a quite different mechanism. 

Superconductor/Ionic Conductor Interfaces A Modem Approach to Surface Roughness 28... 

The two copper oxide layers can be considered as polymeric since the covalent character is in the same range as for the carbon fluoride bond in Teflon. Thus, the 123-superconductors consist of two types of polymeric copper oxide layers held together by ionic bonding metals such as barium and yttrium. This theme of polymeric layers held together by ionic bonding to metals is common in the silicates and other minerals. 

Keywords Charge transfer solid Electronic dimensionality Functional organic solid Ionicity diagram Organic metal Organic superconductor Phase transition Quantum spin liquid state Switching... 

An outline of possible ion substitutions in the new 1-2-3 superconductor (90 K material) based on ionic radii is presented in Table 12. 

The theory above has been applied in a variety of realistic situations. The range includes ionic conductance in aqueous solutions and molten alkali chlorides, damped spin-wave behaviour in paramagnetic systems, stimulated emission of radiation in masers, the fractional quantum Hall effect and quantum correlations in high-Tc cuprates and other non-BCS superconductors [4, 5, 7, 8, 14, 30]. In the next section we will also make some comments on the problem of long-range transcorrelations of protons in DNA [31]. 

---