The characterisation of nanoscopic domains concerning crystal structure and composition is the prerequisite to understand the thermoelectric performance of complex oxides.
Planar faults such as Ruddleston Popper RP defects can govern the properties of functional perovskite-type phases, such as novel n-type thermoelectric oxides e.g. CaMn0.92Nb0.08O3.
Although the influence of this microstructural feature on transport properties of the material was suggested since years only recently it became possible to directly demonstrate this phenomenon via atomic resolution HAADF contrast in combination with modelling and atomic column-resolution EELS.
This work was carried out in the group of Prof. Anke Weidenkaff in collaboration with EMPA.
L. Bocher, M. H. Aguirre, D. Logvinovich, A. Shkabko, M. Trottmann and A. Weidenkaff;
"CaMnxNb1-xO3 (x ≤ 0.08) Perovskite-Type Phases as Promising New High-Temperature n-Type Thermoelectric Materials"
Inorg. Chem., 47, 8077-8085, (2008);
A. Weidenkaff, U. Bangert and M. Aguirre;
"Structure and Composition of Nanoscopic Domains in Functional Perovskite-Type Materials"
Chimia, 60, 742-748, (2006);