Magnetic-field-induced decrease of the spin Peltier effect in Pt/Y3Fe5O12 system at room temperature

Abstract

We report the observation of magnetic-field-induced suppression of the spin Peltier effect (SPE) in a junction of a paramagnetic metal Pt and a ferrimagnetic insulator Y 3 Fe 5 O 12 (YIG) at room temperature. For driving the SPE, spin currents are generated via the spin Hall effect from applied charge currents in the Pt layer, and injected into the adjacent thick YIG film. The resultant temperature modulation is detected by a commonly-used thermocouple attached to the Pt/YIG junction. The output of the thermocouple shows sign reversal when the magnetization is reversed and linearly increases with the applied current, demonstrating the detection of the SPE signal.We found that the SPE signal decreases with the magnetic field. The observed suppression rate was found to be comparable to that of the spin Seebeck effect (SSE), suggesting the dominant and similar contribution of the low-energy magnons in the SPE as in the SSE. * IGUCHI.Ryo@nims.go.jp 1 arXiv:1709.08997v1 [cond-mat.mtrl-sci]

Magnon polarons in the spin Peltier effect

“…To measure the SPE-induced temperature modulation, we follow the experimental method shown in Ref. [38]. We first attached an E-type thermocouple (TC) on top of the middle of the Pt strip by pasting GE-varnish thinly [ Fig.…”

“…3(d), where H ||x. For the electric detection of the SPE, it is important to exclude the large contribution from the Joule heating of the Pt layer [36][37][38]. To this end, we applied a square-wave charge current J c with amplitude ∆J c [ Fig.…”

“…c)][38]. Here, the Joule-heating-induced temperature modulation (∝ ∆J 2 c ) takes a constant value in time [V offset in…”

Combinatorial investigation of spin-orbit materials using spin Peltier effect

“…As a model system, we choose a hybrid structure consisting of a composition-spread paramagnetic Pt-W alloy film and a ferrimagnetic yttrium-iron-garnet (YIG) substrate. Although the Pt/YIG (W/YIG) junction is typically used for measuring the SPE 17 , 19 , 20 , 22 because of the relatively-large positive (negative) spin Hall angle of Pt (W), the spin-charge conversion capability in Pt-W alloys has not been systematically investigated so far. The composition-spread Pt-W film was fabricated on an YIG substrate and patterned into meandered structure by co-sputtering Pt and W through a metallic shadow mask (see Fig.…”

“…Therefore, by measuring the SPE-induced temperature change near the interface, one can obtain information on the magnitude and sign of the DSHE in PM. The DSHE-driven SPE have been observed by means of electrical measurements using thermocouple sensors 16 , 20 and active infrared emission microscopy based on the lock-in thermography (LIT) 17 – 19 , 21 – 25 . Importantly, the LIT technique can visualize the spatial distribution of temperature change due to the DSHE-driven SPE with high temperature and spatial resolutions.…”