Trans-scale spin Seebeck effect in nanostructured bulk composites based on magnetic insulator

Area of Science:

• Condensed matter physics
• Materials science
• Spintronics

Background:

• The spin Seebeck effect utilizes thermally generated spin currents for thermoelectric conversion.
• Conventional devices are limited to nanoscale thin films, restricting power output due to diffusion lengths.
• A need exists for scalable spin Seebeck devices with enhanced power generation.

Purpose of the Study:

• To demonstrate a trans-scale spin Seebeck effect in nanostructured bulk composites.
• To overcome the limitations of nanoscale thin-film architectures for thermoelectric power generation.
• To establish a scalable platform for integrating spin caloritronics with macroscopic devices.

Main Methods:

• Fabrication of Pt-coated yttrium iron garnet (YIG) bulk composites using dynamic powder sputtering and low-temperature sintering.
• Characterization of the 3D composite structure, revealing continuous Pt channels and mechanical integrity.
• Transverse thermoelectric measurements to assess spin Seebeck signals at the bulk scale.

Main Results:

• Demonstration of isotropic spin Seebeck signals in the bulk composite material.
• Evidence of scalable volumetric thermoelectric power generation surpassing diffusion-limited thin films.
• Successful creation of a 3D architecture overcoming nanoscale constraints.

Conclusions:

• The developed nanostructured bulk composites enable a trans-scale spin Seebeck effect.
• This approach offers a scalable pathway for thermoelectric power generation, bridging nanoscale and macroscale integration.
• The study paves the way for practical, high-power spin Seebeck thermoelectric devices.