We report synchrotron x-ray diffraction investigations of interfacially engineered oxygen octahedral rotations and their impact on strain relief in perovskite $\mathrm{SrRu}{\mathrm{O}}_3$ films. We show that octahedral rotations with distinct patterns and magnitudes can be accommodated into coherently grown films. The $\mathrm{SrRu}{\mathrm{O}}_3$ film grown directly on the $\mathrm{GdSc}{\mathrm{O}}_3$ substrate has the $\mathrm{Ru}{\mathrm{O}}_6$ octahedral rotation with the $a^{-}{b}^{+}{c}^{-}$ pattern in the Glazer notation and the rotation angles of ${\alpha }_{\mathrm{rot}}=6.6\pm 0.2^{\circ }, {\beta }_{\mathrm{rot}}=5.5\pm 0.2^{\circ }$, and ${\gamma }_{\mathrm{rot}}=3.6\pm 0.2^{\circ }$. On the other hand, when a 1-nm-thick $\mathrm{BaTi}{\mathrm{O}}_3$ layer without $\mathrm{Ti}{\mathrm{O}}_6$ rotations is inserted between the $\mathrm{SrRu}{\mathrm{O}}_3$ and $\mathrm{GdSc}{\mathrm{O}}_3$, the $\mathrm{SrRu}{\mathrm{O}}_3$ has the $\mathrm{Ru}{\mathrm{O}}_6$ rotation with $a^{-}{b}^0{c}^{+}$, and ${\alpha }_{\mathrm{rot}}=5.6\pm 0.8^{\circ }$ and ${\gamma }_{\mathrm{rot}}=3.6\pm 0.8^{\circ }$. These results indicate that there are some degrees of freedom in the octahedral rotations accommodated in $\mathrm{SrRu}{\mathrm{O}}_3$ depending on the interface structure and that the ${\gamma }_{\mathrm{rot}}$ rotations play the important roles in the film's structural properties when the rotation about the ${\left[010\right]}_{\mathrm{pc}}$ axis is blocked. We also found that the strain relief in the film is influenced by the interfacially engineered octahedral rotations. The interfacial $\mathrm{BaTi}{\mathrm{O}}_3$ layer results in the in-plane periodic lattice modulation in the t-SRO film, allowing for the anisotropic relief of the substrate-induced strain. The results highlight the importance of the interface structure as a factor, determining not only octahedral rotations in coherently grown SRO films but also the strain reliefs in them.

• Received 7 April 2016
• Revised 2 June 2016

DOI:https://doi.org/10.1103/PhysRevB.94.024112