Long-distance spin transmission is essential for spintronic devices. The spin transmission properties are often examined using lateral non-local spin devices. In this work, with the hope of a long-distance spin superfluid transmission, we devise a non-local spin device platform employing single-crystalline NiO films and the spin–orbit precession effect. We scrutinize the non-local voltage signals with possible contributions of spin transport, thermal transport, charge current leakage, and the Joule heating in mind. It is found that the non-local voltage signals in our device are dominated by non-spin contributions raised by a combination of the Joule heating and the charge current leakage, making extraction of spin signal challenging. Our findings are broadly relevant as the Joule heating is usually inevitable when a sufficient amount of spin current should be generated in such spin devices.
Sugiura et al. (2026) studied this question.