Nickel-Gold Alloy: A Breakthrough in High-Efficiency Thermoelectric Materials

A research team at the Vienna University of Technology (TU Wien) in Austria has made a significant breakthrough in the field of thermoelectrics, identifying a nickel-gold alloy as a highly efficient material for converting heat into electricity. Published in Science Advances, their findings highlight the potential of metallic alloys in thermoelectric applications, traditionally dominated by semiconductors due to their favorable Seebeck coefficients.

Source:TUwein Michael Parzer, Fabian Garmroudi and Andrej Pustogow (from left)

Thermoelectric materials work by generating an electrical voltage from the movement of charged particles across a temperature gradient. The efficiency of this process is measured by the Seebeck coefficient. While common metals like copper, silver, and gold typically exhibit low Seebeck coefficients, the TU Wien physicists have discovered that adding about 10% nickel to gold significantly enhances its thermoelectric performance. This improvement is attributed to the energy-dependent scattering of electrons, where nickel's electronic properties cause positive charges to scatter more than negative ones, creating an imbalance that results in a high thermoelectric voltage.

credits: Fabian Garmroudi Source:TUwien

The nickel-gold alloy not only demonstrates exceptionally high electrical conductivity but also achieves a Seebeck coefficient surpassing that of conventional semiconductors, leading to unprecedented thermoelectric power factor values. Such performance suggests the alloy could be used in a variety of applications, from powering smartwatches with body heat to converting industrial waste heat into green electricity.

Despite the high cost of gold, the researchers view their discovery as a proof of concept, showing that metals can indeed possess remarkable thermoelectric properties suitable for practical applications. They are also exploring alternative alloys that do not rely on expensive materials, aiming to broaden the applicability and accessibility of efficient thermoelectric generators.

Reference: High thermoelectric performance in metallic NiAu alloys via interband scattering, Source: Click here