The atomic motion of oxygen in a c-axis-oriented YBa2Cu307 z film was studied with implanted ' 0 as a tracer. Conventional annealing in an oxygen Aowing ambient was performed for 1 hour at various temperatures between 175 and 550 C. Analysis by secondary-ion mass spectroscopy shows that the implanted ' 0 starts to migrate within the YBa2Cu307 z film at a low temperature, between 250 and 300 C. Results from gas/solid oxygen isotopic exchange shows that at 315'C oxygen can enter the YBa2Cu307 z film and confirms the high mobility of oxygen within the film even at this low temperature. The apparent volume di6'usivity of the oxygen at 315'C is found to be -1.5X10 ' cm /s. Shortcircuit di6'usion is thought to play an important role in determining the high mobility of oxygen in the c-axis-oriented YBa2Cu307 z film.

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A c-axis oriented YBa2Cu3O7−δ film, 180–230 nm thick, deposited onto 〈100〉 LaAlO3 by dc sputtering was irradiated at room temperature with 50 keV 2H+ (deuterium) ions to a dose of 1×1016 cm−2. Secondary-ion-mass spectroscopy analysis shows that after implantation the implanted 2H is trapped in both the film and the substrate. For example, when the thickness of the YBCO film is equal to ∼180 nm, it contains about 4.5% of the retained dose. The as-implanted 2H distribution is essentially Gaussian-like and the depth (R̂p) of maximum 2H concentration is ∼485 nm. It is obvious that the target crystallinity has to be taken into account for the range data, since the experiment values (R̂p,R̄p, and ΔRp) are obviously larger than the corresponding values from the transport of ions in matter code. This implantation makes the YBa2Cu3O7−δ film more granular. Within the irradiated LaAlO3 substrate, a damaged band was observed by cross-sectional transmission electron microscopy, which was centered at about 85% of R̂p(exp).

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Thin films (∼0.43 and ∼0.95 μm thick) of YBa2Cu3O7−δ on (100) LaAlO3 substrates have been implanted with 800 keV Ag+ to a dose of 5×1014/cm2, at room temperature (i.e., the total range ≈0.4 μm and the damage level ≈3.1 displacements per atom) and at elevated temperatures (450, 650, and 780 °C), followed by an in situ annealing schedule in flowing oxygen ambient. We have found that the implantation at room temperature amorphizes the implanted layer. In such a case, the implanted layer cannot regrow to the superconducting phase if there is no crystal seed remaining in the bottom of the film, whereas implantation at elevated temperatures plus an in situ annealing schedule, including a step at 870 °C in flowing oxygen ambient, can maintain the crystal structure and superconductivity of the films. For the thicker film, we have found that after the implantation at 450 or 650 °C and the in situ annealing, the total volume of the film has recovered to the superconducting 123 phase with a Tc=89 K.