Session D40 - Poster Session I.
POSTER session, Monday afternoon, March 12
Exhibit Hall, Washington State Convention Center
Titanium dioxide (TiO_2) thin films have been deposited on Si, MgO and SrTiO_3 (STO) substrates by pulsed laser deposition (PLD) and dc sputtering technique. For the case of PLD, pure anatase(001) or rutile(110) TiO_2 films with smooth surfaces have been obtained either by the oxidation of titanium nitride (TiN) films or by the deposition of TiO_2 films directly at different temperatures and oxygen pressures. The YBa_2Cu_3O_7(YBCO) thin films then deposited sequentially on the TiO_2 layers by PLD. The zero-resistance temperature (Tco) for the YBCO films deposited on TiO_2/Si(100) and TiO_2/STO(100) were 85 K and 89 K, respectively. Comparative studies of depositing YBCO films directly on to a dc sputtered TiO_2/STO(100) template commonly used in selective epitaxial growth (SEG) process have, however, resulted in non-superconducting YBCO top layer. The characteristics of the resultant TiO_2 layers obtained from various processes were analyzed to delineate the apparent discrepancies. Experiments of resolving the possible interface layer formation such as Auger electron spectroscopy (AES) depth profile analyses and the interfacial x-ray absorption spectroscopy (XAS) are expected to give more insight on this matter.