Spin Current Response in Bi-YIG/Pt Thin Film Heterostructures Induced by Gamma Radiation

Most of the present solid-state nuclear radiation detectors require cooling to low temperatures for their operation. Herewith, we are reporting the observation of a room temperature spin current response to gamma radiation from a novel Bi-YIG/Pt thin film hetero-structure device. A pulsed laser deposition technique was used to fabricate a 45-nm thick Bi-YIG film over which a 5-nm thick Pt film was deposited by an e-beam technique. Films were thoroughly characterized using energy dispersive X-ray spectroscopy and atomic force microscopy. Sensitivity of the Bi-YIG/Pt thin film device to gamma radiation was tested by investigating the strength of the inverse spin Hall effect voltage generated in the Pt layer on exposing the device to gamma radiation flux. Our results show that even for a very small flux source, a room-temperature spin current response is detectable.