We have deposited YBa2Cu3O7-δ(YBCO) films with low microwave surface resistance (Rs) on 5-cm-diam, oxide-buffered sapphire substrates by planar magnetron sputtering. MgO buffer layers are used on M-plane (101̄0) sapphire, and R-plane (11̄02) sapphire is buffered by CeO2. Rs values of 450-620 μΩ at 77 K and 10 GHz were measured across an entire 5-cm diam YBCO film on M-plane sapphire. For YBCO on R-plane sapphire, Rs values at 77 K and 10 GHz were 950 μΩ for a 5-cm-diam wafer and 700 μΩ for 1×1 cm2 samples.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)