HG-1212 AND HG-1223 SINGLE-CRYSTALS - SYNTHESIS AND CHARACTERIZATION

Single crystals of HgBa2CaCu2O6+delta (Hg-1212) and HgBa2Ca2Cu3O8+delt a (Hg-1223) were grown from the melt at an argon pressure of 10 kbar. Electron microscopy, as well as single crystal X-ray diffraction studi es show that the crystals are well ordered. The EDS analysis indicates the presence of a minor amount of other cations replacing Hg, Ba and Ca in the structure. Refined fractional coordinates and thermal parame ters are given for a crystal of Hg-1223 type. Magnetic and resistive m easurements show a T-c of 133 K for the Hg-1223 phase.