Planar Weight Disparity:  Essential to HTSC?

Over 140 New Superconductors Lend Strong Support


15 October 2011
Last revision: Sept. 2017
Superconductors.ORG

       Superconductors.ORG herein reports more than 140 new superconductors have now been discovered since planar weight disparity (PWD) was found to be a key component of high temperature superconductivity in 2005 (list at page bottom). This suggests strongly that PWD is not just a Tc-enhancement mechanism, but an essential component of high temperature superconductivity in the copper-oxides.


       The latest PWD discovery is a Sn-Tl-Pb-Tm oxy-cuprate with Tc near 105K (see plot page top). Within this material's 1223/1212 intergrowth structure (shown at left) exists PWD in both the C1 and C2 axes. In the C1 axis (heavy) Thallium and Lead alternate with (lighter) Tin. And in the C2 axis, two Thulium atoms alternate with a single Thulium atom.

       The discovery of PWD has made possible new formulations whose predominant weight is shifted from the insulating layers to the CuO2 planes. And this has opened up a wealth of new superconductor possibilites. Since 2005 the application of planar weight disparity has produced the first room-temperature superconductor and 10 improved versions of the industrial superconductor YBCO. The first resonant superconductor and the first high-temp reentrant superconductor have also resulted.

       Re-examining older superconductors also shows that PWD exists in the well-known legacy structures from the 1980's (see below graphics).

          

       The validation of PWD in promoting Tc lends further evidence that HT superconductivity is a function of lattice vibrations. A wave moving through a crystal lattice will slow down and compress when it encounters a heavier region. And it has long been known that compressing a superconductor typically increases Tc. PWD creates regions of compression throughout the lattice. The below graphics illustrate how a wave moving along the C axis in a Pb-3212 structure compresses in the insulating layers as heavier elements are encountered.

    

The list of 137 superconductors created through the application of PWD is shown below.


    

RESEARCH NOTE: The copper-oxides are strongly hygroscopic. All tests should be performed immediately after annealing.

E. Joe Eck
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