Faster production method cuts time for heat-conversion material in half
Researchers have adapted a quicker manufacturing technique to produce high-entropy alloys that convert heat to electricity with comparable efficiency to slower methods. The advance could accelerate commercialization of thermoelectric materials for industrial heat recovery and power generation, where speed and scalability determine economic viability.
Originaltitel: Co-Cr-Fe-Mn-Ni Oxide as a Highly Efficient Thermoelectric High-Entropy Alloy
<p>Among the existing materials for heat conversion, high-entropy alloys are of great interest due to the tunability of their functional properties. Here, we aim to produce single-phase high-entropy oxides composed of Co-Cr-Fe-Mn-Ni-O through spark plasma sintering (SPS), testing their thermoelectric (TE) properties. This material was successfully obtained before via a different technique, which requires a very long processing time. Hence, the main target of this work is to apply spark plasma sintering, a much faster and scalable process. The samples were sintered in the temperature range of 1200-1300 degrees C. Two main phases were formed: rock salt-structured Fm (3) over barm and spinel-structured Fd (3) over barm. Comparable transport properties were achieved via the new approach: the highest value of the Seebeck coefficient reached -112.6 mu V/K at room temperature, compared to -150 mu V/K reported before; electrical properties at high temperatures are close to the properties of the single-phase material (sigma = 0.2148 S/cm, sigma approximate to 0.2009 S/cm reported before). These results indicate that SPS can be successfully applied to produce highly efficient TE high-entropy alloys in a fast and scalable way. Further optimization is needed for the production of single-phase materials, which are expected to exhibit an even better TE functionality.</p>