CuPt Alloy Thin Films for Application in Spin Thermoelectrics

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Spin thermoelectrics offer a novel approach to energy conversion, potentially surpassing the efficiency limits of traditional thermoelectric devices governed by the Wiedemann-Franz law.
• Conventional spin thermoelectric devices commonly utilize platinum due to its strong spin-orbit coupling (SOC).

Purpose of the Study:

• To investigate the performance of copper-platinum (CuPt) alloys as an alternative to platinum in spin thermoelectric devices.
• To explore the potential of CuPt alloys to enhance the spin Seebeck voltage and overall efficiency.

Main Methods:

• Fabrication of CuPt alloy films with varying platinum concentrations deposited on yttrium iron garnet (YIG) films.
• Characterization of device performance using spin Seebeck measurements under identical conditions.

Main Results:

• The Cu$_{0.4}$Pt$_{0.6}$ alloy film demonstrated a nearly threefold increase in spin Seebeck voltage compared to pure platinum.
• The enhanced performance is attributed to the higher electrical resistivity and improved spin Hall angle of the CuPt alloy.

Conclusions:

• Copper-platinum alloys represent a promising material for advancing spin thermoelectric device efficiency.
• The findings suggest that optimizing alloy composition can lead to significant improvements in spin thermoelectric performance, overcoming limitations of pure platinum.