Recently, several creative processing techniques yielded thermoelectrics with reduced thermal conductivity and, thereby, an enhanced figure or merit. These were based on engineered complex microstructures with attendant dislocation structures. In this study, we implement highly controlled mesoscopic dislocation structures into the model thermoelectric SrTiO 3 in order to quantify phonon scattering at dislocations. Both single crystals and polycrystalline material have been furnished with enhanced dislocation densities increased by a factor of 150-300 by plastic deformation. Thermal conductivity was measured using laser flash analysis between room temperature and 325 C. Etch pit techniques and ultra-high voltage electron microscopy afford quantification of dislocation density. Experimental results were compared to predictions by the Debye-Callaway model. The latter revealed that dislocation densities of 10 15 m À2 would be necessary for the reduction of thermal conductivity of SrTiO 3 in the investigated temperature range, which could not be realized using the plastic deformation mechanism applied.

The transformation towards a circular economy based on sustainable technologies requires future-oriented materials development, which considers materials recycling with a minimum environmental impact (EI). This demands a holistic approach towards...