Anisotropic thermoelectric transport in the Sr 2 RuO 4 − Ru eutectic system
Year: 2026
Type: article
Abstract: The Sr 2 RuO 4 − Ru eutectic system, in which metallic Ru inclusions are embedded in an Sr 2 RuO 4 matrix, exhibits an enhanced superconducting onset temperature of about 3 K, known as the 3-K phase. Here, we investigate the in-plane thermoelectric response of this eutectic system in the normal state and find a pronounced anisotropy in the thermopower for thermal gradients applied parallel and perpendicular to the Ru lamellae. To clarify its origin, we combine thermopower measurements with electronic-structure-based transport calculations and finite-element modeling of the local strain distribution generated by the thermal-expansion mismatch between Sr 2 RuO 4 and Ru. The calculations show that uniaxial compression of Sr 2 RuO 4 produces a sizable thermopower anisotropy through modification of the Fermi surfaces. When an idealized spatially inhomogeneous strain field around the Ru lamellae is included, the observed sign and qualitative magnitude of the anisotropy are reproduced more closely than in a simple unstrained two-component model. These results are consistent with a substantial contribution from strain-induced changes in the Sr 2 RuO 4 electronic structure near the interfaces, although contributions from interfacial phase mixing and three-dimensional transport connectivity cannot be excluded.
Source: APS Open Science
DOI: 10.1103/y7n6-pchv
Institution: Tokyo University of Science
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W7223106198