TY - JOUR A1 - Chen, Cong A1 - Giovannelli, F. A1 - Delorme, F. T1 - Thermoelectric properties of Fe2-xTi1+xO5 solid solutions: Influence of microcracking and Nb substitution T2 - Ceramics International N2 - The synthesis route and thermoelectric characterization of n-type Fe2-xTi1+xO5 (0 ≤ x ≤ 0.5) and Fe1.75(Ti1-yNby)1.25O5 (0 ≤ y ≤ 0.05) are presented. Their electrical conductivity obeys the small polaron model and their Seebeck coefficient is weakly dependent on temperature. The carrier concentration is increased with increasing Ti content in Fe2-xTi1+xO5, thus improving the electrical conductivity and decreasing the absolute values of the Seebeck coefficient. The composition with x = 0.5 shows reduced electrical conductivity contradicting the change in the carrier concentration, as it contains more microcracks than the other compositions. Fe2-xTi1+xO5 exhibits extremely low thermal conductivity. Fe2-xTi1+xO5 with x = 0.25 exhibits the highest ZT, ~ 0.014 at 1000 K. Therefore, a limited extent microcracks are beneficial to thermoelectric properties; however, when they are too extended they can be detrimental. On the contrary to Fe2TiO5, Nb substitution into Fe1.75Ti1.25O5 does not obviously improve its thermoelectric properties. PB - Elsevier CY - Amsterdam KW - Thermoelectric KW - Pseudobrookite KW - Fe2TiO5 PY - 2018 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/46299 AN - OPUS4-46299 SN - 0272-8842 SN - 1873-3956 VL - 44 IS - 17 SP - 21794 EP - 21799 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany