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oai:docta.ucm.es:20.500.14352/1035232025-09-01T17:50:41Zcom_20.500.14352_14col_20.500.14352_15

Structural Characterization and Thermoelectric Properties of Br-Doped AgSnm[Sb0.8Bi0.2]Te2+m Systems Delgado, Daniela Moris, Silvana Valencia Gálvez, Paulina López García, María Luisa Álvarez Serrano, Inmaculada Blake, Graeme R. Galdámez, Antonio Herein, we report the synthesis, structural and microstructural characterization, and thermoelectric properties of AgSnm[Sb0.8Bi0.2]Te2+m and Br-doped telluride systems. These compounds were prepared by solid-state reaction at high temperature. Powder X-ray diffraction data reveal that these samples exhibit crystal structures related to the NaCl-type lattice. The microstructures and morphologies are investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDS), and high-resolution transmission electron microscopy (HRTEM). Positive values of the Seebeck coefficient (S) indicate that the transport properties are dominated by holes. The S of undoped AgSnm[Sb0.8Bi0.2]Te2+m ranges from +40 to 57 mu V.K-1. Br-doped samples with m = 2 show S values of +74 mu V.K-1 at RT, and the Seebeck coefficient increases almost linearly with increasing temperature. The total thermal conductivity (kappa(tot)) monotonically increases with increasing temperature (10-300 K). The ktot values of undoped AgSnm[Sb0.8Bi0.2]Te2+m are similar to 1.8 W m(-1) K-1 (m = 4) and similar to 1.0 W m(-1) K-1 (m = 2) at 300 K. The electrical conductivity (sigma) decreases almost linearly with increasing temperature, indicating metal-like behavior. The ZT value increases as a function of temperature. A maximum ZT value of similar to 0.07 is achieved at room temperature for the Br-doped phase with m = 4. 2024-04-25T15:57:24Z 2024-04-25T15:57:24Z 2024-04-25T15:57:24Z 2023 journal article https://hdl.handle.net/20.500.14352/103523 XXXX-XXXX 10.3390/ma16155213 1996-1944 eng 190856 Delgado, D.; Moris, S.; Valencia-Gálvez, P.; López, M.L.; Álvarez-Serrano, I.; Blake, G.R.; Galdámez, A. Structural Characterization and Thermoelectric Properties of Br-Doped AgSnm[Sb0.8Bi0.2]Te2+m Systems. Materials 2023, 16, 5213. https://doi.org/10.3390/ma16155213 http://creativecommons.org/licenses/by/4.0/ open access Attribution 4.0 International MDPI