Enhanced spin-to-charge conversion in epitaxial La0.67Sr0.33MnO3/NdNiO3 bilayers at the nickelate metal-insulator phase transition

Abstract Phase transition materials such as NdNiO 3 (NNO) when coupled with low damping ferromagnets such as La 0.67 Sr 0.33 MnO 3 (LSMO) hold the promise for developing new multi-functional material systems harnessing the interplay of charge, spin, and orbital degrees of freedom. In this study, we probe the evolution of spin-to-charge conversion in epitaxial all-oxide LSMO (12 nm)/NNO (4, 8, and 16 nm) bilayers. Using spin pumping ferromagnetic resonance, we track the spin-to-charge conversion within the NNO layer through the paramagnetic metal to antiferromagnetic insulator transition and observe a pronounced enhancement of the inverse spin Hall effect signal at the onset of this phase transition. We attribute this enhancement to the electronic and magnetic disorder in NNO at the first-order phase transition, thereby providing insights into the mechanism of spin transport through the phase transition. The tunability of spin-to-charge conversion in this low damping bilayer system offers a pathway for developing reconfigurable, energy-efficient spintronic devices.