Superconductor structural data

X-ray crystallography, 40 20-21 synthetic models, 40 23-48 xanthane oxidase, 40 21-23 chalcogenide halides, 23 370-377, 413 Chevrel phases, 23 376-377 metal-metal bonding, 23 330, 373 structural data, 23 373-376 as superconductors, 23 376 synthesis, 23 371-372 chloride, 46 4-24, 35-44 heterocations of, 9 290, 291 cluster compounds, 44 45-46 octahedral, 44 47-49, 53-63 electronic structure, 44 55-63 molecular structure, 44 53-54 synthesis, 44 47-49 rhomboidal, 44 75-82 solid-state clusters and, 44 66-72, 74-75, 80-82, 85-87 tetrahedral, 44 72-75 triangular, 44 82-87 cofactor, 40 2, 4-12 anaerobic isolation, 40 5 molybdopterin and, 40 4-8 reduced form, 40 12 synthesis, 40 8-12 xanthine oxidase, 45 60-63 complexes... 

Otto H, Baltmsch R, Brandt H-J (1993) Further evidence for H " in H-based superconductors from improved bond strength parameters involving new structural data of cubic TI2O3. Phy sica C215 205-208... 

Table 4.2-11 Electrical and structural data of selected low-Tc oxide superconductors...

Electrical and Structural Data of High-Tc Superconductors. In Tables 4.2-13 and 4.2-16 electrical and structural data, respectively, of selected high- Tc cuprates are summarized. The data were compiled on the basis of review articles [2.13-16]. In many cases the real stoichiometric coefficients of oxygen are a few tenths higher or lower than the one-digit numbers indicated in the formulas of the tables. The value A7[ is the difference between the temperatures at which the resistance reached 90% and 10% of the normal state resistance, respectively, during cooling of the sample p Q) is the residual resistivity expressed by the formula p T> Tc) = p(P) + piT) with p = dp/dT. 

As shown in Fig. 4.2-16 of Sect. 4.2.1, the Bi superconductors have a layered perovskite structure which is composed of superconducting Cu02/Ca stacks (one stack in Bi2201, two stacks in Bi2212, and three in Bi2223) sandwiched between insulating BiO and SrO planes. The structural data of the compounds are presented in Table 4.2-27. 

Having identified methods to deposit conductive polymer and molecular metal systems onto cuprate superconductor structures without damage to either material, it becomes important now to consider the electronic interactions that occur when the two conductors are in contact with one another. Of particular importance is the interaction that occurs between the polymer-derived charge carriers and the superconducting Cooper pairs. Important background information related to this area can be obtained from the well-documented behavior of the more classical metal/superconductor and semicon-ductor/superconductor systems. Thus, prior to considering experimental data and theoretical treatments for organic conductor proximity effects, we review previous studies of proximity effects in the more classical systems. 

The temperature dependence of the poly(3-hexylthio-phene)/Pbo.. Bii.7Sri,6Ca 2.4CU3O10 contact resistance above displays an activated behavior, with the contact resistance increasing as the temperature is lowered from room temperature to 110 K (Fig. 37.14A). However. as Tc(onset) is approached, the contact resistance decreases dramatically. Unlike data acquired with normal metal/high-Tc structures, where the values of the contact resistance become vanishingly small below 7, the contact resistance for the polymer/superconductor structure possesses a small but finite value at low temperatures. The presence of a short segment of polymer that extends onto the insulating matrix and is not in di-... 

The intent of this chapter is twofold. One is to give brief structural descriptions of many of the copper-oxide superconductors. For in-depth information, the reader is referred to the original publications. The second is to provide detailed crystallographic information (lattice constants, positional and thermal parameters, space groups, etc.), and compositional data on many of the superconductors discussed. Also, calculated x-ray powder diffraction patterns for these same compounds are tabulated. It is hoped that such information will prove useful to the superconductivity researcher. 

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