|About this Abstract
||Materials Science & Technology 2019
||Late News Poster Session
||P2-15: Crystal Growth and Characterization of Anisotropic Thermoelectric Compounds
||David Smiadak, Alex Zevalkink, Nicolas Perez Rodriguez, Geoffroy Hautier, Richard Staples, Gabi Schierning
|On-Site Speaker (Planned)
Grain boundaries play an important role in the electronic and thermal transport properties of many thermoelectric materials. However, to isolate grain boundary contributions, it is necessary to compare the properties of polycrystalline and single crystal samples. In the present study, the low temperature electronic properties of Ca5M2Sb6 (M=Ga, In) have been studied as both polycrystalline and single crystal form to quantify the contributions from grain boundaries and crystalline anisotropy to the electronic mobility.
Single crystals of Ca5Ga2Sb6, Ca5In2Sb6, and alloyed composition Ca5GaInSb6 have been grown successfully using the flux method. Structural characterization using single crystal X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy are coupled with surface energy calculations for the purpose of studying the free surface morphology of the crystals. Single crystals were cut using a focused ion beam, and a novel photolithography approach was utilized to apply a circuit allowing for low temperature thermoelectric transport characterization.