High-pressure synthesis and heat treatments of (Hg1-xBix)Sr2Ca2Cu3Oy

The stabilization of the third member (n = 3) of HgSr2Can-1CunOy family by Bi substitution is the subject of this report. Bulk samples containing (Hg, Bi)Sr2Ca2Cu3Oy as a main phase (>90%) were synthesized using a high-pressur e high-temperature technique under 6 GPa and 1000 degrees C. They were char acterized by X-ray powder diffraction (XRD), electron diffraction (ED), tra nsmission electron microscopy (TEM) and DC susceptibility measurements. The as-prepared samples exhibit T-c with onset of about 107 K. Heat treatments in Ar atmosphere increased the T-c onset up to 112 K. (C) 1999 Published b y Elsevier Science B.V. All rights n:served.