The heat harvesting will be based on phase transformation materials (PTMs) exhibiting large and abrupt changes in a physical property at a certain temperature. The change can e.g. be structural, magnetic, or electrical, giving rise to shape memory alloys, thermomagnetic, and pyroelectric materials. These are physical phenomena that have been known for some time, but applications have been scarce due to severe problems with hysteresis and stability. However, recent progress in the theory of such transformations has in principle solved these issues, and the path is open to devices that can convert heat to electricity with efficiencies close to the thermodynamic limit (the Carnot efficiency).
The COMET project will benefit from this development through collaboration with the groups that developed the theory. It will further develop and merge a whole suite of new techniques that are specifically aimed towards identifying novel PTMs with superior properties for energy harvesting. This includes the following advances at the frontier of this field:
- The first true ab initio calculation of pyroelectric coefficients.
- The first identification of a complete set of descriptors (defining parameters) targeted at PTMs.
- The first high-throughput screening modelling study on PTMs based on first principles, exploiting the exceptional efficiency of the temperature-dependent effective potential method.
- The first synthesis of compositionally graded films for high-throughput experimental search and validation of theoretically predicted PTM properties.
- The first study linking first-principles calculations, synthesis, and characterization of microscopic and functional properties of multiferroic PTMs.
The project partners are:
SINTEF, Materials Physics, Ole M. Løvvik, Patricia A. Carvalho, Øystein Dahl, Spyros Diplas, Marit Stange: First-principles calculations, high-throughput experimental synthesis, functional property assessment, various characterization.
University of Oslo, Structure physics, Anette Gunnæs, Ole B. Karlsen: Electron microscopy, sample synthesis, various characterization.
University of Minnesota, Richard D. James: Multi-crystalline bulk samples, applications.
The Hong Kong University of Science and Technology, Xian Sherry Chen: Single crystal synthesis, crystallography of phase transformations.
California Institute of Technology, Austin Minnich: First-principles calculations.
Postdoctoral scholarship: Nicholas Pike. Nick has his Phd in analytical modeling and postdoctoral experience in first-principles modeling of electronic, vibrational, and thermal properties of transition metal compounds. He is currently developing methods for modeling of PTM materials and the pyroelectric coefficient from a first-principles calculation.
PhD scholarship: Monika Løberg. Monika has her MSc from University of Oslo, and will in this project conduct electron microscopy and other experiments.
Guest scientist: Amina Matt. Amina works in the project as part of her internship at SINTEF. She is working to finish her MSc degree at EPFL in Switzerland.
The Frinatek program, The Research Council of Norway