Pulsed laser deposition of YBa2Cu3O7-delta thin films in high oxygen partial pressures

Pulsed laser deposition of YBa2Cu3O7-delta (YBCO) coated conductors was studied for the range Of P(O-2) from 120 mTorr to 1200 mTorr, higher than typically used oxygen partial pressures during deposition. The purpose of the investigation was to determine the sensitivity of YBCO film quality to varying P(O-2) for scaled-up fabrication of long-length coated conductors. Deposition at high P(O-2) (greater than or equal to 400 mTorr) gave very high and more consistent critical temperatures (T-c = 92 +/- 0.4 degreesK) than results obtained at lower oxygen partial pressures (less than or equal to 200 mTorr) as determined by magnetic susceptibility measurements. Typically, the lower partial pressures are used although the laser fluence used in this research (3.2 J/cm(2)) is higher than typical. Transport J(c)'s were consistantly high for a wide range of oxygen pressures, 5 - 8 x 10(6) A/cm(2) at 77 K, self-field for P(O-2) = 200 - 1200 mTorr. These results indicate that pulsed laser deposition of YBCO is relatively insensitive to P(O-2) at the higher pressures of oxygen considered.