Physical Chemistry Chemical Physics · 2012 · 190 citations · 32 references
Natural SciencesMaterials EngineeringMaterials ScienceCondensed Matter PhysicsMaterials PhysicsSolid State PhysicsHeat Transfer In SolidsHigh-temperature MaterialsPhase TransitionsRare-earth-doped MaterialsThermal Properties Of MaterialsThermoelectric MaterialsHigh-temperature ThermoelectricsSynchrotron DiffractionSynchrotron X-ray CharacterizationSynchrotron X-ray CrystallographySynchrotron X-ray DiffractionThermoelectric Energy ConversionThermoelectric PropertiesThermoelectric Transport Coefficients
This work elucidates the possible reasons for the outstanding, but never reproduced thermoelectric properties of the doped Ti(0.5)Zr(0.25)Hf(0.25)NiSn Heusler compounds. The structural investigations done via synchrotron X-ray diffraction measurements and scanning electron microscope measurements, which clearly show that the microstructure consists of three temperature stable C1(b) phases with possible semi-coherent interfaces, are presented. The exceptional thermoelectric properties are due to this intrinsic phase separation. It is possible to reproduce the high Figure of Merit values with ZT = 1.2 at 830 K. Furthermore, the influence of doping different elements on the Sn position in this Heusler material system is investigated.
32