EFFECTS OF IN DOPING IN HG1-XINXBA2CACU2O6+DELTA

Indium-doped samples of Hg1-xInxBa2CaCu2O6+delta (hereafter symbolized as (Hg1-xInx)-1212) with x = 0, 0.1, 0.2, 0.4 and 0.5 have been synth esized in sealed silica tubes by the solid state reaction method. The precursor can be prepared in air. The effects of In doping in Hg(In)-1 212 superconductor have been investigated by x-ray diffraction, resist ance and susceptibility measurements, scanning electron microscopy (SE M), electron probe microanalysis (EDX) and thermogravity analysis tech niques. Experimental results show that a small amount of In doped in H g-1212 promotes the formation of compound Hg(In)-1212 which has two Cu O2 layers. The stability of the product compounds is also enhanced. Th e volume fraction of the impurity phase HgCaO2 is reduced obviously in the In-doped samples. However, the critical temperature of the In-dop ed Hg(In)-1212 is slightly decreased. A maximum of about 5% (x = 0.05) of In can be doped into the crystal structure of Hg-1212. The solubil ity of the In makes the lattice parameter c decrease as compared to th e pure Hg-1212 phase.