Journal article

Publication year: 2021

Journal: Materials Today Physics

Volume number: 21

ISSN: 2542-5293

Open access status: Green

DOI Link: https://doi.org/10.1016/j.mtphys.2021.100471

Publisher: Elsevier

Abstract: 
Carrier transport in Mg2Si1-xSnx thermoelectrics was experimentally found to be highly sensitive to high temperature heat treatment and in particular the role of the precise Mg content has been discussed controversially. Considering this, electrical transport properties of Sb doped Mg2Si0.4Sn0.6 were measured in-situ during annealing at 710 K. We measured two quasi-identical samples: sample 1, for the Seebeck coefficient and the electrical conductivity (sigma) measurement in helium, and sample 2 for Hall coefficient and sigma measurement in vacuum, respectively. Both samples largely remain single phase and did not show de-mixing after annealing for similar to 276 hours and similar to 1100 hours respectively. The observed experimental data can be modelled using a single- and two parabolic band model and a continuous reduction in majority carriers is identified, which can be linked to Mg loss. Thorough analysis furthermore reveals mobility loss and a lowering of the density of states effective mass which could both be due to ongoing Mg loss or due to a lifted degeneracy of conduction bands in Mg2Si0.4Sn0.6 at room temperature. Finally, we can link the change in carrier concentration to a change in Mg-related defects and identify a phase width Delta delta in Mg2-delta Si0.4Sn0.6. (C) 2021 Elsevier Ltd. All rights reserved.

Harvard Citation style: Sankhla, A., Kamila, H., Naithani, H., Mueller, E. and de Boor, J. (2021) On the role of Mg content in Mg₂ (Si,Sn): Assessing its impact on electronic transport and estimating the phase width by in situ characterization and modelling, Materials Today Physics, 21, Article 100471. https://doi.org/10.1016/j.mtphys.2021.100471

APA Citation style: Sankhla, A., Kamila, H., Naithani, H., Mueller, E., & de Boor, J. (2021). On the role of Mg content in Mg₂ (Si,Sn): Assessing its impact on electronic transport and estimating the phase width by in situ characterization and modelling. Materials Today Physics. 21, Article 100471. https://doi.org/10.1016/j.mtphys.2021.100471