Effects of Ultrathin TiO x Seeding Layer on Crystalline Orientation and Electrical Properties of Sputtered (Ba,Sr)TiO 3 Thin Films

A series of ultrathin TiO x (0–12 nm) seeded (Ba,Sr)TiO 3 (BST) thin films have been prepared on Pt (111)/TiO x /SiO 2 /Si substrates by RF‐magnetron sputtering. Experimental results show that an ultrathin TiO x layer acts as an initial template for the BST films in the first nucleation stage, resulting in a significant influence on crystalline orientation and electrical characteristics of the resultant BST films. Interestingly, highly (111) oriented BST film [α (111) ∼97%] with 5‐nm‐thick TiO x seeding layer exhibits a shifted Curie temperature ( T c =275 K) and an enhanced tunability of 61.16% at 400 kV/cm, when compared with (001)‐oriented BST without TiO x layer ( T c =250 K and tunability=50.05%).