The effect of In 2 O 3 on grain connectivity and superconducting properties of Bi-2212 was investigated. Indium was intentionally doped on the Sr-site of BSCCO at doping levels from x = 0 to x = 0.8. Accessing the Sr lattice site in BSCCO provides useful control on the possible effect of indium on its superconducting behavior and microstructural properties. Results show that the superconductivity persists in BSCCO even at high indium concentration (x = 0.8). However, secondary phases form at x ≥ 0.4 indium concentration affecting normal resistivity, magnetic susceptibility response and superconducting transition temperature of BSCCO. Formation of secondary phases weakens the diamagnetic intergrain coupling. An apparent increase in the formation of micron-sized grains is related to the increased sinterability of BSCCO with indium doping. The enhanced sinterability of BSCCO with indium provides possibility of synthesizing thin films with reduced thermal heat treatment.

Indium oxide (In2O3) films grown by thermal oxidation on MgO substrates were optically excited by femtosecond laser pulses having photon energy lower than the In2O3 bandgap. Terahertz (THz) pulse emission was observed using time domain spectroscopy. Results show that THz emission saturates at an excitation fluence of ~400 nJ/cm2. Even as two-photon absorption has been excluded, the actual emission mechanism has yet to be confirmed but is currently attributed to carriers due to weak absorption from defect levels that are driven by a strain field at the interface of the substrate and the grown film.