Probing length-scale separation of thermal and spin currents by nanostructuring YIG

Abstract

We have fabricated bulk nanostructured ferrimagnetic materials with different grain sizes by sintering ball-milled Y3Fe5O12 (YIG) nanoparticles and measured the grain-size dependence of the thermal conductivity and spin Seebeck thermopower. The nanostructuring reduces both thermal conductivity and thermopower, but the reduction of the latter was found to be considerably stronger despite the moderate difference in magnetization, which suggests that the length scales of transport of magnons and phonons contributing to the spin Seebeck effect are significantly larger than that of phonons carrying thermal current. This is consistent with the measurements of high-magnetic-field response of the spin Seebeck thermopower and low-temperature thermal conductivity, where the quenching of magnons seen in single-crystalline YIG was not observed in nanostructured YIG due to scattering of long-range low frequency magnons.

References in corpus (6)

• Direct electronic measurement of the spin Hall effect
• Thermoelectric generation based on spin Seebeck effects
• Electrical detection of spin pumping due to the precessing magnetization of a single ferromagnet
• Thermal imaging of spin Peltier effect
• Quantitative Temperature Dependence of Longitudinal Spin Seebeck Effect at High Temperatures
• Concomitant enhancement of longitudinal spin Seebeck effect with thermal conductivity

Cited by in corpus (7)

• Transverse thermoelectric generation using magnetic materials
• Spin and spin current -- From fundamentals to recent progress
• Spin Seebeck Effect: Sensitive Probe for Elementary Excitation, Spin Correlation, Transport, Magnetic Order, and Domains in Solids
• Magnetic-field-induced suppression of spin Peltier effect in Pt/${\mathrm{Y}}_3\mathrm{F}{\mathrm{e}}_5{\mathrm{O}}_{12}$ system at room temperature
• Role of Magnon-Magnon Scattering in Magnon Polaron Spin Seebeck Effect
• Anomalous Ettingshausen effect in iron-carbon alloys
• Temperature dependence of the mean magnon collision time in a spin Seebeck device