under uniaxial strain

Sr₂RuO₄ is a candidate for chiral odd-parity superconductivity with T_c~1.5 K, an interpretation supported by an unchanged ¹⁷O and ¹⁰¹Ru hyperfine shifts upon cooling through T_c. Recently, compressive strain was associated with a sharp peak in T_c, T_c^max~3.5 K, and connected to a Van-Hove Singularity (VHS). Normal state ¹⁷O NMR spectra, recorded at low temperature and in samples subject to compressive strain, exhibit corresponding singularities in hyperfine shifts. The results deviate significantly relative to expectations for the VHS, in that impacted susceptibilities are inferred to originate not just with d_xy orbitals, but also d_yz, d_xz. ¹⁷O NMR measurements in the superconducting state of strained samples are underway.