Exploring Multi-Component Superconducting Compounds by a High-Pressure Method and Ceramic Combinatorial Chemistry

In this short review, we provide some new insights into the material synthesis and characterization of modern multi-component superconducting oxides. Two different approaches such as the high-pressure, high-temperature method and ceramic combinatorial chemistry will be reported with application to several typical examples. First, we highlight the key role of the extreme conditions in the growth of Fe-based superconductors, where a careful control of the composition-structure relation is vital for understanding the microscopic physics. The availability of high-quality LnFeAsO (Ln = lanthanide) single crystals with substitution of O by F, Sm by Th, Fe by Co, and As by P allowed us to measure intrinsic and anisotropic superconducting properties such as Hc2, Jc. Furthermore, we demonstrate that combinatorial ceramic chemistry is an efficient way to search for new superconducting compounds. A single-sample synthesis concept based on multi-element ceramic mixtures can produce a variety of local products. Such a system needs local probe analyses and separation techniques to identify compounds of interest. We present the results obtained from random mixtures of Ca, Sr, Ba, La, Zr, Pb, Tl, Y, Bi, and Cu oxides reacted at different conditions. By adding Zr but removing Tl, Y, and Bi, the bulk state superconductivity got enhanced up to about 122 K.

High pressure, low benefits [microform] : unfair practices in selling Medigap and other insurance to the elderly : hearing before the Subcommittee on Housing and Consumer Interests of the Select Committee on Aging, House of Representatives, One Hundredth Congress, first session, June 24, 1987.

"Comm. pub. no. 100-707."

Research and development on high-pressure-high-temperature metallurgy,

Cover title.

Design, performance, fabrication and material considerations for high-pressure vessels /

"March 1964."

Survey of available high pressure pneumatic components : (5,000 PSI and UP) /

"July 1954."

Seamless steel tubing: high-temperature, high-pressure service.

"Technical bulletin 6H."

Research and development on the effects of high pressure and temperature on various elements and binary alloys,

"Materials Central, Contract no. 33(616)-5995. Project no. 7351.

Equipment serviceability criteria for compressor, reciprocating, air, power driven, high pressure, 4 CFM and up, 1000 PSI and up, group I--four wheel MTD, pneumatic tires, GED, Davey mdl P-4, Joy mdls 15HGPS-MSI and 15HGP9-MSI, Joy mdl WK-80 15H1, Joy mdl 415HGP3-MSI, Ingersoll-Rand mdl P4R 15 G-J, Stewart-Warner mdl 12021A ...

"20 June 1973"--P. 1.

A study of high pressure transmission losses /

Cover title: A study of high tensions losses.

Feasibility study of a coal slurry feeding system for high pressure gasifiers; final report.

Mode of access: Internet.

High-pressure adsorption of supercritical gases on activated carbons: An improved approach based on the density functional theory and the bender equation of state

Adsorption of nitrogen, argon, methane, and carbon dioxide on activated carbon Norit R1 over a wide range of pressure (up to 50 MPa) at temperatures from 298 to 343 K (supercritical conditions) is analyzed by means of the density functional theory modified by incorporating the Bender equation of state, which describes the bulk phase properties with very high accuracy. It has allowed us to precisely describe the experimental data of carbon dioxide adsorption slightly above and below its critical temperatures. The pore size distribution (PSD) obtained with supercritical gases at ambient temperatures compares reasonably well with the PSD obtained with subcritical nitrogen at 77 K. Our approach does not require the skeletal density of activated carbon from helium adsorption measurements to calculate excess adsorption. Instead, this density is treated as a fitting parameter, and in all cases its values are found to fall into a very narrow range close to 2000 kg/m(3). It was shown that in the case of high-pressure adsorption of supercritical gases the PSD could be reliably obtained for the range of pore width between 0.6 and 3 run. All wider pores can be reliably characterized only in terms of surface area as their corresponding excess local isotherms are the same over a practical range of pressure.