Growth of YBa2CU3O7-delta thin films in pulsed laser deposition: influenceof target, substrate and deposition rate

The growth of smooth, high quality, c-axis thin films of optimally doped YB a2Cu3O7-delta on (001) MgO substrates has been studied using pulsed laser d eposition. The films were characterized with Auger spectroscopy, x-ray diff raction, self-inductance and four-probe resistance techniques. We have foun d an interesting interaction between deposition rate, substrate topography and target oxygenation in the determination of film quality. The best films are produced with dense underoxygenated targets at low laser repetition ra tes (1 Hz) on very smooth substrates; the optimal deposition parameters For these are given. Atomic force microscopy shows spiral growth formations wi th a unit-cell edge height. Oriented outgrowths observed on some films are attributed to heat-modified substrate surface morphology. a-asis films also have been grown using PrBa2Cu3Ox template layers.