Transition temperature, superconductivity

Figure C 1.2.7. Superconducting transition temperature plotted as a function of the a lattice parameter for a variety of A Cgg phases [55].

Rhenium hexafluoride is a cosdy (ca 3000/kg) material and is often used as a small percentage composite with tungsten or molybdenum. The addition of rhenium to tungsten metal improves the ductility and high temperature properties of metal films or parts (11). Tungsten—rhenium alloys produced by CVD processes exhibit higher superconducting transition temperatures than those alloys produced by arc-melt processes (12). 

Titanium alloyed with niobium exhibits superconductivity, and a lack of electrical resistance below 10 K. Composition ranges from 25 to 50 wt % Ti. These alloys are P-phase alloys having superconducting transitional temperatures at ca 10 K. Thek use is of interest for power generation, propulsion devices, fusion research, and electronic devices (52). 

Isotope Effects on Superconductivity. Substitution of hydrogen by deuterium affects the superconducting transition temperature of palladium hydride [26929-60-2] PdH2 (54,55), palladium silver hydride, Pd Ag H D ( 6), and vanadium—2itconium—hydride, N(57). 

Fig. 12. Normalized dc electrical resistivity p(T) of single crystal KsCeo. The inset shows the p(T) behavior near the superconducting transition temperature Tc = 19.8 K [114]. The curvature in p(T) for T > Tc is due to the volume expansion of the sample [7, 4.3],...

It will be intriguing to theoretically examine the possibility of superconductivity in CNT prior to the actual experimental assessment. A preliminary estimation of superconducting transition temperature (T ) for metallic CNT has been performed considering the electron-phonon coupling within the framework of the BCS theory [31]. It is important to note that there can generally exist the competition between Peierls- and superconductivity (BCS-type) transitions in lowdimensional materials. However, as has been described in Sec. 2.3, the Peierls transition can probably be suppressed in the metallic tube (a, a) due to small Fermi integrals as a whole [20]. 

Electrical Resistivity 75 oDcm Superconductive Transition Temperature <1.2K Hall Constant -0.47x10"4 cm /A s... 

Electrical Resistivity 37-45 pDcm Superconductive Transition Temperature < 1.2K Hall Constant -12.4 x lO " cm A s Magnetic Susceptibility -23 x 10 emu/mol... 

Electrical Resistivity 35 pGcm Superconductive Transition Temperature 6K Hall Constant -1.3 x 10 " cmVA s Magnetic Susceptibility +15.3 x 10 emu/mol... 

Electrical Resistivity 17-22pDcm Superconductive Transition Temperature lO.OK Hall Constant - 21.8 x 10 " cm /A s at20°C Magnetic Susceptibility + 10 x 10 emu/mol... 

Superconductive Transition Temperature 2-8.7 K (varies with composition)... 

Melting temperatures Tm and superconducting transition temperatures Tc of some solders [14-21]... 

TES suffer from some limitations such as the small useful temperature range and the non-linearity of the transition curve. The latter drawback is especially evident in roughly patterned TES, as in the case shown in Fig. 15.5 [25], Feedback techniques, similar to those used in electronic amplifiers, minimize these drawback, reducing also the TES time response [26], The superconducting transition temperature (sometimes quite different from those of the bulk metal) of a TES made with one metal layer (single layer) depends on the metal used and on the film thickness. 

An initial attempt was made to correlate the structural properties of the kl-(BEDT-TTF)2M(CF3)4(TCE) salts with their superconducting transition temperature [31]. The relationship between Tc and any single unit cell parameter failed to show any discemable trend. The best correlation was obtained by plotting Tc as a function of the b/c ratio, where b is the interlayer and c is an intralayer direction. A similar conclusion was reached through the determination of uniaxial pressure coefficients of p -(BEDT-TTF)2SF5CH2CF2S03 and k-(BEDT-TTF)2Cu(NCS)2 through the measurement of thermal expansion [32]. These results also indicated that expansion of the interlayer direction and compression of an intralayer direction... 

Fig. 3 Chart illustrating the superconducting transition temperatures as a function of solvent and anion in the KL-(BEDT-TTF)M(CF3)4(l,l,2-trihaloethane) (M = Cu, Ag and Au) series. 1120 is 1,1,2-trichoroethane, lBrl2Cl is l-bromo-l,2-dichloroethane, llC12Bris 1,1-dichloro-2-bromoethane, lC112Br is 1-chloro-1,2-dibromoethane and 112Bris 1,1,2-tribromoethane...

The electrodeposited precursor films, annealed in air at 870 °C in the presence of a TBSBCCO pellet, produce a biaxial textured Tl-1223 phase, as confirmed by an XRD pole-figure measurement. The omega and phi scans indicate full-width at half-maximum (FWHM) values of only 0.92° and 0.6°, respectively, which indicates a very high-quality film. The superconductive transition temperature of the Tl-1223 film, determined resistively, was about 110 K. Figure 7.11... 

The normal spinel Li[Ti2]04 is a metallic oxide with a superconducting transition temperature of 13.7 K. The nominal formula is Li+[Ti3+Ti4+]04, in which the Li+ ions occupy the tetrahedral sites while the octahedral sites contain titanium with an average charge Ti3 5+, although as the material is metallic at room temperature the electrons are delocalized in a partly filled 3d band. 

Figure 8.8 Variation of the superconducting transition temperature, Tc, with oxygen content ...

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