Influences of Heat Treatment on Superconducting Properties of Bi1.7Pb0.3(nanoTi0.2)Sr2Ca2Cu3O10+d Thin Film Deposited on Different Substrates

Films of Bi1.7Pb0.3Sr2Ca2Cu3O10+d with the addition of 0.2 nanoparticles TiO2 were deposited on different substrates such as crystalline Si and MgO by pulse laser deposition method. Deposited samples have been annealed at different temperatures 820 and 840 °C for two hours in oxygen environment. Annealed films were characterized structurally by X-ray diffraction and morphologically by two techniques: scanning electron microscopy and atomic force microscopy. Energy dispersive X-ray spectrometric was utilized to provide compositional information of the thin films. Structural analysis displayed that two superconducting phases coexist in the samples high Bi-2223 and low Bi-2212 phases. Namely, the DC. resistivity measurements show that all the samples exhibit the metallic behavior. It has been observed the transition temperature (TC ) for films deposited on Si substrate found at 115 and 117 K are higher than those deposited on MgO substrate which were found at 114.5 and 116.5 K for at 820 and 840 °C respectively. Additionally, it has been noted with increasing the annealing temperature, the sample exhibits the smoothest and densest surface morphology confirming that more Ti nanoparticles penetrate into grains or over grain boundaries of the film. This is correlating with the enhancement of the connectivity between the grains.