**3. Crystal structures**

The XRD 2 theta-omega scan of the FeRhO<sup>3</sup> films is shown in **Figure 4(a)**. For the as-deposited sample, broad peaks are observed at 35 and 75°, which are ascribed to the (110) and (220)

**Figure 4.** (a) XRD 2θ/ω scan of the FRO film (*x* = 1.0) grown on TTO/*α*-Al<sup>2</sup> O3 (110). (b) XRD pattern of the FRO film (*x* = 0.2) grown on the FTO substrate. (c) Magnified image of the XRD pattern of (b). [Copyright (2012 and 2014), The Japan Society of Applied Physics].

reflections of corundum-type FRO, respectively. This indicates that the films grown along [110] despite their low crystalline quality. Sharp peaks appear after thermal annealing, suggesting an improvement in the crystallinity. The in-plane epitaxial relationship was evaluated to be TTO [010]//FRO [001] by in-plane XRD measurements. This result agrees with the atomic configurations in **Figure 3(a)** [30]. The lattice constants obey Vegard's law, implying that Fe had been appropriately substituted with Rh. In contrast to the films deposited onto the sapphire substrates, the films deposited on the glass substrates are polycrystalline in nature, as shown in **Figure 4(b)** and **(c)**.
