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It is found that rubidium Rb 1+ substitution into the "2212" bismuth superconductors, Bi 2( Sr 1−x Rb x)2 CaCu 2 O 8+y (x = 0.05, 0.1, 0.15, 0.2, and 0.3), produces changes in the copper valency which correlate with changes in the transition temperatures T c . By liquid nitrogen quenching pellets sintered at 800°C, nearly constant oxygen contents are obtained in all pellets fabricated. The c axis length is found to decrease with increasing Rb doping level.

The effect of the magnetic properties of YBCO superconductors on the inductance of coil were studied in order to the dependence on temperature of effective penetration depth and the variation potential difference for damped oscillation in RLC series circuit. In this work, The samples of YBa2Cu3-xAgxO7- were prepared by solid state reaction in air at 950 ๐C for 24 hr. serves as the core of solenoids. The inductance of solenoids changes up with the increasing of temperature from boiling point of liquid nitrogen (77 K) to room temperature had been measured. Then we calculated to the effective penetration depth. We found that there were increase correspond with the increasing of temperature and the critical temperature decreased and then increased with the increase in Ag2O concentration of x = 0.1 and 0.2 , respectively. The variation potential difference for damped oscillation in RLC series circuit. We found that the decreasing of amplitude per cycle of the samples at superconducting state larger than those at normal state and phases shift in the damping oscillattion of RLC circuit at superconducting state are less than that at normal state, discussed as in inductance, the magnetic flux entering through the samples at superconducting state are less than that at normal state.

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The silicate glass was prepared using rice husk as the source of silica. The base composition of glass sample was 46SiO2 (from rice husk ash)-19Na2CO3-18H3BO3-13ZnO-3CaO-0.9Al2O3-0.2Sb2O3 mol %. Doping with copper oxide yielded the colored silicate glass. The expansion coefficients of the copper doped glass was 10.76 x 10-6 K-1. The finger prints of the bond vibrations were studied using IR spectroscopy. While the oxidation state and the coordination information of the copper ion in the glass matrix were investigated using X-ray absorption spectroscopy. From the data, Cu+ and Cu2+ exist in the glass matrix.