MELT-TEXTURED CERAMIC SUPERCONDUCTORS - FAST-MELT FAST-QUENCH PROCESSIN A SOLAR FURNACE

A texturizing method for ceramic superconductors involving a new way f or rapid melting and quenching in a solar furnace is presented. The me thod involves rapid melting of a silver-doped YBCO rod suspended in an evacuated quartz tube at a temperature exceeding 2000 degrees C follo wed by rapid quench on a silver mould. The sample obtained is melt-tex tured in a tube furnace. The melt-textured product exhibits high criti cal current density of the order of 10(4) A/cm(2) in the field of 1 T at 50 K. This property is discussed in the framework of pinning center s introduced in our materials during the rapid melting and quenching p rocess. Nonsuperconducting phases created during the quenching process serve as these pinning centers.