0.9BiFeO(3)-0.1BiCoO(3) (BFCO) films (t = 100 nm) were prepared on orthorhombic YAlO3 (YAO) (100) substrates by r.f. magnetron sputtering. Film flatness, crystallinity, crystal symmetry, and secondary phase formation are strongly affected by the pressure of the sputtering gasses. Ar and O-2. Phi-scan measurements showed that the films were epitaxially grown on the substrates, with the crystal relation [101](p)(101)(p) BFCOII[101](p)( 101)(p) YAO. X-ray reciprocal space mapping revealed that the crystal symmetry of the BECO films was a pseudo-cubic-like monoclinic structure, with M-C phase, rather than the Cm symmetry of the bulk BFCO. Cross-sectional transmission electron microscopy analysis revealed that the film had, as a result of a lattice misfit of 7%, strong compressive strain less than 10 nm from the interface, which relaxed monotonically with increasing distance from the interface. Magnetic measurements show that strained monoclinic BFCO has smaller magnetization compared to rhombohedral BFCO. (C) 2014 Elsevier B.V. All rights reserved