Thermoelectricity offers the unique possibility of a direct conversion of heat to electricity. Half-Heusler compounds based on TiNiSn are of great interest for thermoelectric research due to their promising electrical properties.
The sequence of experimental images reveals topography and Volta Potential Difference changes resulting from irreversible phase segregation on the grain boundaries within the Ti-rich intergranular phase.

This work was carried out in the groups of Prof. Anke Weidenkaff (EMPA) and Prof. Jürg Hulliger.

References:

• K. Galazka, S. Populoh, L. Sagarna, L. Karvonen, W. Xie, A. Beni, P. Schmutz, J. Hulliger, A. Weidenkaff;
  "Phase formation, stability, and oxidation in (Ti, Zr, Hf)NiSn half-Heusler compounds"
  Phys. Status Solidi A, 211, 1259-1266, (2014); doi:10.1002/pssa.201300209 and
  Phys. Status Solidi A, 211, Issue 6 Cover, (2014); doi:10.1002/pssa.201470235.