Epitaxial thin films of BiScO3, a compound which is thermodynamically unstable under ambient conditions, were grown on BiFeO3-buffered SrTiO3 substrates despite the very large lattice mismatch between the film and the substrate. The epitaxial BiScO3 films retain all principal structural features of high-pressure bulk BiScO3 (i.e. octahedral tilting and the pattern of Bi displacements) that give rise to a pseudo-orthorhombic unit cell. Films grown on (100) substrates adopt the bulk monoclinic structure whereas films on the (110) substrates exhibit a somewhat different symmetry. The dielectric permittivities were modest (~30) with low loss tangents (<1% at low fields); no maxima were observed over the temperature range of -200 and +350°C. There is no evidence of significant hysteresis (either ferroelectric or antiferroelectric) at room temperature up to the breakdown strength of the films.
Citation: Journal of Applied Physics
Pub Type: Journals
bismuth scandate, distortions, electron microscopy, perovskite