Films superconducting thin ceramic

The second main part of a PLD system is the vacuum chamber. The author s group developed a large-area PLD process for the double-sided deposition of high-Tc superconducting thin films (see for example [8,10]). As substrate heater an arrangement of KANTHAL wire in ceramic tubes is used... 

Electrical and Electronic Applications. Silver neodecanoate [62804-19-7] has been used in the preparation of a capacitor-end termination composition (110), lead and stannous neodecanoate have been used in circuit-board fabrication (111), and stannous neodecanoate has been used to form patterned semiconductive tin oxide films (112). The silver salt has also been used in the preparation of ceramic superconductors (113). Neodecanoate salts of barium, copper, yttrium, and europium have been used to prepare superconducting films and patterned thin-fHm superconductors. To prepare these materials, the metal salts are deposited on a substrate, then decomposed by heat to give the thin film (114—116) or by a focused beam (electron, ion, or laser) to give the patterned thin film (117,118). The resulting films exhibit superconductivity above Hquid nitrogen temperatures. 

The importance of materials science to U.S. competitiveness can hardly be overstated. Key materials science areas underlie virtually every facet of modem life. Semiconductors underpin our electronics industry. Optical fibers are essential for communications. Superconducting materials will probably affect many areas ceramics, composites, and thin films are having a big impact now in transportation, construction, manufacturing, and even in sports—tennis rackets are an example. 

Gilbert, L.R., Messier, R. and Roy, R., Superconducting BaPbj xBixOs Ceramic Films Prepared by R.F. Sputtering. Thin Solid Films 54 129 (1978). 

Routes to monomeric , mononuclear , monolanthanide alkoxides, enolates, siloxides and aryloxides - an expanded title which will put the scope of the article in a more concrete form. The synthesis of mononuclear alkoxides, in particularly homoleptic derivatives [1], was decisively stimulated by the discovery of high temperature superconducting ceramics based on YBa2Cu307<, where yttrium represents the lanthanide elements [2]. The support of volatile and highly soluble molecular precursors is a prerequisite for synthesizing thin films of these materials by means of MOCVD [3] and sol gel processes [4], respectively. More recently, lanthanide alkoxide reagents became established in... 

The new superconducting ceramics offer a way out, if they can be made in some workable form, probably a thin film, and so long as the circuits can be operated at around 80° K or higher. The oxides could then be used on the circuit chips themselves to connect transistors and other devices and to make connections between chips. There is also the possibility that the superconducting properties in the new materials can be manipulated by, say, moving oxygen in and out as needed, or that the ceramics will turn out for some reason to be more suitable than conventional superconducting materials for use in transistors. 

Many relevant properties and already commercially available applications of ceramic superconductors are listed in Tables 9.7 and 9.8 it is important to note that LTS operate at low temperatures, close to 4K (liquid helium), while HTS operate from the temperature of liquid helium to 77 K (liquid nitrogen). Although limited details of these materials are described in the following sections, the electronic applications which often employ thin films or type 1 superconducting metals have been partly omitted. 

Note that the issue of the brittleness of ceramics restricting their application is not limited to structural applications. For instance, the brittleness of superconducting ceramics had to be resolved by employing them either as thin films on ductile metal wires or embedded within ductile metal casings. Thus the understanding of how to defeat the brittleness of the ceramics impacts their use in a host of applications. 

Ceramic superconducting films are divided into three classes, Bl-type compounds, ternary compounds, and high-temperature oxide superconductors. The Bl-type (NaCl-type structure) compound superconductors consist of nitrides and carbides with 5A, 6A, and 7A transition metals, such as TiN, ZrN, HfN, VN, NbN TaN, MoN, WN, TiC, ZrC, HfC, VC, NbC, TaC, MoC, WC, NbNi tC t, hex-MoN, and hex-MoC. Regarding the thin-film material, it is notable that NbN and NbN] (C ( (x = 0.08 and 0.15) have superconducting critical temperature, T, values of 17.3 and 17.8 K, respectively. The deposition method used is almost always sputtering or CVD. The properties of films deposited by the former method are superior. A highly reliable Josephson device was realized with an NbN film. 

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