Covalent bonds in superconducting rapid cooled alloys: (Bi1.7Pb0.3Sr2Can‐1CunO2n+4+δ)2, n=1 to 9 detected by local atomic enhanced XRD

Authors

J. Kmiec, San José State University
K. Tyson, San José State University
Juana Acrivos, San José State University
D. Gulamova, Academy of Sciences of Uzbekistan
J. Chigvinadze, E. Andronikashvili Institute of Physics

Document Type

Presentation

Publication Date

April 2012

Publication Title

Mills College

Disciplines

Chemistry

Abstract

High temperature layer superconducting cuprates (HTLSC) alloys: (Bi1.7Pb0.3Sr2Can-1CunO2n+4+δ)2,n=1-9 called (2s:2:n-1:n) prepared in Uzbekistan from melts in concentrated sun flux, followed by rapid cooling, SFQA technology that preserves melt tiling by confinement of conduction layer: |(CuO2)1/2|Ca|(CuO2)1/2]n-1| in the hard shell ||, of the n=1 phase,[(CuO2)1/2|SrO|Bi1.7Pb0.3O|Bi1.7Pb0.3O|SrO|(CuO2)1/2]2. Disproportion leads to different n-phase mixing, and periodic lattice distortions (PLD) through bond resonance covalent crystalaxes: 2(rCu+2+rO-2)=4.2Å>a=3.82Å>d(CuO)+2-3/2d(O3))=3.2Å≈(cn-c1)/2(n-1). Individual phase local bonds Cu-Ca, Cu-Sr, Cu-O-Cu are ascertained by X-Ray diffraction near Cu K-edgefollowed by Cu-Ca bond scattering. The HTLSC density, ρ decrease as n increases obtains Tc,n ~180 K, identified due to n=8 phase on the surface of bulk n=4. Thus, bond resonanceleads to higher n phases on surface and predicts: Tc,n ⇒298K as n⇒50, if the superconducting skin depth is within c50, of a few μm even in mixed n phases.

Comments

Poster Presentation.

Recommended Citation

J. Kmiec, K. Tyson, Juana Acrivos, D. Gulamova, and J. Chigvinadze. "Covalent bonds in superconducting rapid cooled alloys: (Bi1.7Pb0.3Sr2Can‐1CunO2n+4+δ)2, n=1 to 9 detected by local atomic enhanced XRD" Mills College (2012).