Low-temperature growth of YBa2Cu3Ox by pulsed laser deposition

We prepared superconducting YBa2Cu3Ox films at lower temperatures (similar to 670 degrees C) by a pulsed laser deposition method. The growth temperature usually decreased with decreasing oxygen pressure in the deposition chamber. However, the superconducting critical temperature (T-c) of the films deposited at a low oxygen pressure was drastically degraded because of insufficient oxidation. In this work, we employed a mixed gas consisting of oxygen and ozone as the oxidation gas. As a result, T-c increased to 86 K, when films were deposited in a low-pressure oxygen atmosphere (5 mTorr) mixed with ozone (5 mol%) and at a low laser fluence of 0.23 J cm(-2). In addition to superconducting properties, the surface morphology could be improved by using low-pressure oxygen gas mixed with ozone and by optimizing the laser fluence.