Superconductors.ORG (joe Eck) announced a way has been found to further increase the record high critical temperature of superconducting material (Tl4Ba)-9223 from 254K to 258K (258 kelvin is -15 celsius and +5 fahrenheit) . This extraordinarily high transition temperature was achieved by substituting magnesium into the calcium atomic sites of the 16-layer 9223 structure that produced 254K superconductivity in 2009. The new formula thus becomes (Tl4Ba)Ba2Mg2Cu7O13+.
When 4-point resistance tests were performed on a sample pellet, multiple plots displayed a sharp resistive transition near 258 Kelvin (-15C, 5F), as shown at page top. This is the first observation of superconductivity over 0F. While four degrees Kelvin is not a huge increase in high Tc, this discovery again validates planar weight disparity as a prolific Tc enhancement tool. It also illustrates the challenges in trying to improve superconductor performance as we approach room temperature. A meissner transition was observed near 260K in this material
Some of Joe’s earlier work was confirmed and published in journals by researchers in the middle east.
As with prior discoveries that are asymmetrical along the C axis, the volume fraction of the 258K material is low (less than 1%). So commercialization will have to wait for a refining method to be developed to increase the VF. As a result of a low VF, numerous R-T and magnetization tests may be necessary to see the respective transitions above the noise. This discovery is being released into the public domain without patent protection in order to encourage additional research. Synthesis was by the solid state reaction method