

218K Superconductor Signature Resolved

World Record Rises 80 Degrees Since May 2006



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An additional copper atom positioned into the 1212C chain of the B212/1212C structure (where B=11 and C=copper chain) causes a branching of the copper chain, creating a B212/2212C structure (shown at left). This extra copper atom increases the hole content of that insulating layer and further stiffens the lattice, raising Tc.



Even though the copper chain branches, the planar weight ratio remains high along the C axis. As with the 212K, 200K, 195K, and prior discoveries, planar weight disparity is the driving force behind these extraordinarily high Tc materials.





Synthesis of these materials was by the solid state reaction method. Stoichiometric amounts of the below precursors were mixed, pelletized and sintered for 36-60 hours at 830C. The pellet was then annealed for 10 hours at 500C in flowing O2.

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The magnetometer employed twin Honeywell SS94A1F Hall-effect sensors with a tandem sensitivity of 50 mv/gauss. The 4-point probe was bonded to the pellet with CW2400 silver epoxy and used 7 volts on the primary.

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

E. Joe Eck

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