2. Environmentally friendly ceramic oxide generating electricity from waste heat

Environmentally friendly ceramic oxide generating electricity from waste heat

  • School of Science/Graduate School of Science
  • Department of Physics
  • (Laboratory of Condensed-Matter Physics of Functional Materials)

Ichiro Terasaki [Professor]


Outline of Seeds

Energy necessary for social activity of human being exponentially increases. It is finally converted into waste heat, which causes serious problems agains the environments. We are requested to use energy as efficiently as possible, for most of energy resources have to be imported to our country. Thermoelectric power generation is one of the most expected technologies for waste-heat recovery. This technology is a direct energy conversion by conduction electrons, and posesses varisous advantages such as long lifetime, high stability, maintenance free (Fig. 1).

Novelty and originality of this research

We discovered good thermoelectric properties in the layered cobalt oxide NaxCoO2. Later, the related oxide Ca3Co4O9 has been applied to device fabrication (Crystal structure is shown in the upper-right, and the photographic image is in the lower-left), and the device is now on sale from TES New Energy (lower-right). We have investigated for the elucidation of the good thermoelectric properties and developed new materials and new measurement systems.

Application and research area for Industry collaboration

We design and synthesize new materials showing large thermopower at high temperatures, and also try to find out photo-induced thermoelectric phenomena (Fig. 2).

Key Takeaway

We are in an age of discovery, and have been searching for new materials which exhibit superior functions to semiconductors developed in the 50's. We have developed new materials and investigated their fundamental physics.


transition-metal oxide, thermoelectrics, organic conductor, nonlinear conduction, ceramics, energy conversion, magnetic material, huge response, strongly correlated electron system, material development, function search in new materials


  • Growth of single-crystal and polycrystalline samples of varisous oxides
  • Precise measurements of resistivity, thermopower, Hall effect, thermal conductivity, dielectric constant, magnetic susceptibility, optical reflectivity, specific heat
  • nonlinear conduction measurement using pyrometry, magnetoelectric/magnetopolarization measurement, thermoelectric measurement using Harman method


  • Quantum Design PPMS, MPMS, Image futnace, X-Ray Diffractometer, FTIR, Box furnaces, TD-DTA, and many homemade equipments

Monographs, Papers and Articles

  • Terasaki, Y. Sasago and K. Uchinokura, "Large thermoelectric power in NaCo2O4 single crystals", Phys. Rev. B56 (1997) R12685-R12687
  • I. Terasaki, R. Okazaki, P. S. Mondal, and Y.-C. Hsieh, "Trials for oxide photo-thermoelectrics", Mater. Renew. Sustain. Energy (2014) 3:29