Ba1-xKxBiO3 Epitaxy on Various Substrate Materials

We have fabricated Ba1-xKxBiO3 (BKBO) films by thermal co-evaporation of the metals K, Ba and Bi. To improve the epitaxy a high temperature BaBiO3 seed layer is deposited prior to the BKBO film which results in TC values up to 24 K on standard substrates. As BKBO grows well on perovskites we deposited thin PrBa2Cu3O7 (PBCO) layers by thermal co-evaporation on MgO, CeO2 buffered sapphire, YSZ buffered Si and YSZ substrates. BKBO films on these systems are epitaxial and show the same Tc values as on standard substrates. Thus, by using a PBCO buffer layer technical substrates are available for BKBO thin films.