SYNTHESIS AND CHARACTERIZATION OF SUPERCONDUCTING SINGLE-CRYSTALS OF HGBA2CA2CU3O8+DELTA

HgBa2Ca2Cu3O8+delta single crystals of submillimeter size were grown in a single-step synthesis under normal pressure. The crystals were examined by X-ray diffraction, energy dispersive X-ray analysis (EDX), scanning electron microscopy and magnetic measurements. The ''as-grown'' single crystals have a T-c of 120 K, as defined by the onset of diamagnetism. After annealing in oxygen at 300 degrees C for 6 h, they can display a sharp superconducting transition temperature as high as 135 K.