Measurement of the heat flux normalised spin Seebeck coefficient of thin films as a function of temperature

Abstract

The spin Seebeck effect (SSE) has generated interest in the thermoelectric and magnetic communities for potential high efficiency energy harvesting applications, and spintronic communities as a source of pure spin current. To understand the underlying mechanisms requires characterisation of potential materials across a range of temperatures, however, for thin films the default measurement of an applied temperature gradient (across the sample) has been shown to be compromised by the presence of thermal resistances. Here, we demonstrate a method to perform low temperature SSE measurements where instead of monitoring the temperature gradient, the heat flux passing through the sample is measured using two calibrated heat flux sensors. This has the advantage of measuring the heat loss through the sample as well as providing a reliable method to normalise the SSE response of thin film samples. We demonstrate this method with an ${\text{SiO}}_2/{\text{Fe}}_3{O}_4/\text{Pt}$ sample, where a semiconducting-insulating transition occurs at the Verwey transition, $T_{\text{V}}$, of ${\text{Fe}}_3{\text{O}}_4$ and quantify the thermomagnetic response above and below $T_{\text{V}}$.

References in corpus (5)

• Observation of the Spin-Seebeck Effect in a Ferromagnetic Semiconductor
• Criteria for accurate determination of the magnon relaxation length from the nonlocal spin Seebeck effect
• Enhancement in Thermally Generated Spin Voltage at Pd/NiFe${}_2$O${}_4$ Interfaces by the Growth on Lattice-Matched Substrates
• Role of spin mixing conductance in determining thermal spin pumping near the ferromagnetic phase transition in EuO_{1-x} and La2NiMnO6
• Spin Seebeck effect and magnon diffusion length in ${\mathbf{Fe}}_3{\mathbf{O}}_4$

Cited by in corpus (1)

• Spin and spin current -- From fundamentals to recent progress