Superconductivity, inorganic polymers

While the focus of current interest is on carbon backbone polymers, we should not overlook poly(sulphurnitride), see Section 4.2.6. SN is an electrically conductive inorganic polymer that becomes superconducting at low temperature (Labes et al., 1979). SNV is obtained as a single crystal material by the solid-state polymerisation of S2N2. Though S2N2 decomposes explosively at... 

Possibly the most important single advance in the field of synthetic inorganic polymers in recent years has been the discovery, in 1973, that polymeric sulphur nitride (SN)n (Polythiazyl) is a metallic-type conductor, which at low temperatures becomes superconducting. Polythiazyl is the first known example of such a polymeric superconductor, which does not contain metal atoms. A history of (SN)r research to 1973, and a review of the chemical properties and preparative... 

TMTSF)20104) , inorganic polymers ((SN) and the (SN)x bromine complex), and graphite complexes (CgK,CgRb, and CgCs) are known which become superconducting at... 

The majority of studies using PR-TRMC in recent years have involved complex organic materials such as conjugated polymers or discotic liquid crystals. Inorganic semiconductor materials have however also received attention over the years. The first of these was a study of the radiation-induced conductivity in a powder sample of the high-Tc superconductor DyBajCujOj,. The superconductivity transition at 88 K on cooling was found to be accompanied by a dramatic, sudden increase in the radiation-induced conductivity an effect which... 

One of the earliest known conductive polymers is polysulfumitride (SN) , an inorganic material that tends to be explosive, but becomes superconducting at 0.3 Since then, many conductive polymers have evolved. The most investigated ones appear to be polyacetylene, polyaniline, polypyrrole, poly thiophene, poly(phenylene sulfide), and poly(phenylene vinylene). 

Even a preliminary investigation of the properties of some inorganic pol5miers reveals that some of them have unexpected properties. Polythi-azyl is an anisotropic electrical conductor and shows conductivity that is comparable to metals. At 0.26 K this polymer becomes superconducting [4, 5]. Polysilanes which contain catenated silicon atoms in a polymeric chain have several unusual properties. These polymers have a o-electron delocalization. They are radiation sensitive and many of them are thermo-chromic. Many members of this family also show nonlinear optical behavior [17, 19]. 

Colloidal dispersions of 33-nm-diameter trimetallic Au-Pb-Cd particles, containing gold core surroimded with a 18-nm-thick lead shell are formed by y-irradiation of corresponding metals salts." Nanocomposites with three or more different metals are multimetallic nanohybrids. Studies of their structures is a challenging task. Nevertheless, these materials have aheady been used as precursors in the production of superconducting ceramics, special multicomponent steels, etc. Traditionally, polymer is formed in a previously prepared inorganic matrix or the polymer is inserted into the latter. Multimetallic nanocomposites are prepared in situ within a polymeric matrix or simultaneously with polymer matrix formation. 

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