P superconductor

Snowden, Donald P., "Superconductors for Power Transmission", Scientific American, Vol. 226, No. 4, April 1972, Page 84 Ross, Marc, "Improving the Efficiency of Electricity Use in Manufacturing", Science, Vol. 244, No. 4902, April 21, 1989, Page 311... 

From an analysis of Cp and susceptibility data NbN has been shown to exhibit a low density of states and this suggested that it is an s-p superconductor and its high 7 is due mainly to a large... 

An s-p superconductor is one in which the electrons or states at the Fermi surface are s and p in character. An s-d superconductor has primarily s and d electrons at the Fermi surface and is usually the case for superconductors containing i/-electron transition elements. 

Phinyocheep, P. Tang, 1. M. Determination of the Hole Concentration (Copper Valency) in the High Superconductors, /. Chem. Educ. 1994, 71, A115-A118. 

C. P. Poole, Jr., T. Datta, and H. A. Farach, Copper Oxide Superconductors, John Wiley Sons, New York, 1988. 

Some of the alkali metal-group 15 element systems give compounds of stoichiometry ME. Of these, LiBi and NaBi have typical alloy stmc-tures and are superconductors below 2.47 K and 2.22 K respectively. Others, like LiAs, NaSb and KSb, have parallel infinite spirals of As or Sb atoms, and it is tempting to formulate them as M+ (E )" in which the (E )" spirals are iso-electronic with those of covalently catenated Se and Te (p. 752) however, their metallic lustre and electrical conductivity indicate at least some metallic bonding. Within the spiral chains As-As is 246 pm (cf. 252 pm in the element) and Sb-Sb is 285 pm (cf. 291 pm in the element). 

High-temperature superconductors, p. 192 Fuel cells, p. 579 Nanotubes, p. 608 Self-assembling materials, p. 649 Conducting polymers, p. 772... 

In the next breath you take, almost all the atoms you inhale will be of elements in the final four groups of the periodic table. Except for the gases containing carbon and hydrogen, air is made up almost entirely of elements from this part of the p block, some as elements and some as compounds. The p-block elements are present in most of the compounds necessary for life and are used to create fascinating and useful modern materials, such as superconductors, plasma screens, and high-performance nanodevices. 

The calculated values of p are shown in Figure 2. Positive values (left of atomic number 41.7) correspond to crest superconductors, and negative to trough superconductors. Values of Tc calculated by introducing p in equation (3) (with 0 = 120°) are represented by the curve in Figure 3, which applies to the elements and the alloys of adjacent elements. The calculation for the alloys was made by use of fractions pt of M+z, Mz, M z, M+z+1, Mz+i, and M-z+i given by a probability function exp[—0.694(a — x0)2] (x = number of electrons)... 

The quantum of magnetic flux is only 2.07 x 10-15 Wb, which is approximately equal to the amount of the earth s magnetic field enclosed by a ring of 10p,m in diameter. The Josephson effect is observed when two superconductors are separated by a very thin insulating layer (about 20 nm). Single electrons and Cooper pairs can tunnel through such a layer. The characteristics of the Josephson junction are now used to define the volt and have enabled the uncertainty in the maintained standard to be reduced to 0.1 p,V. 

The effect of deuterium isotope substitution on Tc has been studied for three members of the KL-(BEDT-TTF)2Ag(CF3)4(l,l,2-trihaloethane) family [12, 34-36]. In all cases, the Tc increased upon deuteration with the effect ranging from 0.21 to 0.36 K. These results are similar to the deuterium isotope effect observed in the p"-(BEDT-TTF)2SF5CH2CF2S03 [34, 37] and k-(BEDT-TTF)2Cu(NCS)2 [38] superconductors. 

Cowan DO, Fortkort JA, Metzger RM (1991) Design constraints for organic metals and superconductors. In Metzger RM, Day P, Papavassiliou GC (eds) Lower-dimensional systems and molecular electronics. NATO ASI Ser, vol B248. Plenum Press, New York,... 

Odier, P. Supardi, Z. De-Barros, D. Vergnieres, L. Ramirez-Castellanos, J. Gonzales-Calbet, J. M. Vallet-Regi, M. Villard, C. Peroz, Ch. Weiss, F. 2004. Spray pyrolysis for high Tc superconductor films. Supercond. Sci. Technol. 17 1303-1310. 

Bhattacharya, R. N. Phok, S. Spagnol, P Chaudhuri, T. 2006. Electrodeposited biaxially textured buffer layer for YBa2Cu307 5 (YBCO) superconductor oxide films. J. Electrochem. Soc. 153 C273-C276. 

High temperature superconductors (HTS), 23 814, 826, 829. See also Anisotropic HTS HTS entries applications of, 23 852-872 layered, 23 827, 840 magnetic phase diagram of, 23 838-842 p- and n-type, 23 838 structural anisotropy and fluxon line fragmentation in, 23 841 thallium- and mercury-based, 23 848-850... 

It is clear that the decrease of the rate of the electron transfer operated by the temperature makes the oxidation of ferrocene become quasi-reversible for both the electrode materials. Moreover, it is noted that for both types of electrode the faradaic current increases with temperature. For both the electrodes the oxidation process is governed by diffusion, since in both cases the plot of log(/p) vs. 1/T is linear. Furthermore, one should note in particular that, contrary to the naive expectation, for the superconducting electrode one does not observe any abrupt change in the response upon crossing the barrier from superconductor (that should exchange pairs of electrons) to simple conductor (that should exchange single electrons). 

Another interesting application of the total energy approach involves superconductivity. For conventional superconductors, the 1957 theory of Bardeen, Cooper and Schrieffer [26] has been subject to extensive tests and has emerged as one of the most successful theories in physics. However, because the superconducting transition temperature Tc depends exponentially on the electron-phonon coupling parameter X and the electron-electron Coulomb parameter p, it has been difficult to predict new superconductors. The sensitivity is further enhanced because the net attractive electron-electron pairing interaction is proportional to X-p, so when these parameters are comparable, they need to be determined with precision. 

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