Spin Seebeck devices using local on-chip heating

TL;DR

This paper demonstrates a micro-patterned spin Seebeck device with on-chip heating, enabling sensitive measurement of spin and thermal effects in small magnetic devices, aligning well with traditional and modeled results.

Contribution

It introduces a novel on-chip heating method for small-area spin Seebeck devices, allowing precise measurement of spin and thermal effects with enhanced sensitivity.

Findings

Successful measurement of longitudinal spin Seebeck effect in small devices

Enhanced sensitivity using lock-in detection for SSE, ANE, and inverse spin Hall effect

Temperature gradient measurements match modeling and large-area results

Abstract

A micro-patterned spin Seebeck device is fabricated using an on-chip heater. Current is driven through a Au heater layer electrically isolated from a bilayer consisting of Fe$_3$O$_4$ (insulating ferrimagnet) and a spin detector layer. It is shown that through this method it is possible to measure the longitudinal spin Seebeck effect (SSE) for small area magnetic devices, equivalent to traditional macroscopic SSE experiments. Using a lock-in detection technique it is possible to more sensitively characterize both the SSE and the anomalous Nernst effect (ANE), as well as the inverse spin Hall effect in various spin detector materials. By using the spin detector layer as a thermometer, we can obtain a value for the temperature gradient across the device. These results are well matched to values obtained through electromagnetic/thermal modeling of the device structure and with large area spin Seebeck measurements.