Year: 2019
Type: article
Abstract: Mg 2 X (X=Si, Sn, and Ge) based systems have attracted widespread attention owing to their various benefits in thermoelectric applications. In particular, to date, ternary Mg 2 X based solid solutions have become one of the most widely investigated thermoelectric systems. However, the investigation of temperature varied thermoelectric properties of Mg 2 X based quaternary systems is rather limited both theoretically and experimentally. Therefore, here, we report a rigorous theoretical work of thermoelectric properties for n-type Mg 2 Si 0.55 − z Sn 0.4 Ge 0.05 Bi z quaternary solid solutions ( z = 0.02, 0.025, 0.03, and 0.035) from 300 K to 850 K. By using nearly-free-electron model together with Fermi–Dirac statistics we define Fermi level both in extrinsic and intrinsic regimes as a function of temperature. We follow Hicks and Dresselhaus’ approach to calculate electronic transport properties. By performing the Debye’s isotropic continuum model a detailed theoretical investigation of lattice thermal conductivity is presented among with various phonon relaxation rates. From our theoretical analysis the highest ZT is attained for Mg 2 Si 0.53 Sn 0.4 Ge 0.05 Bi 0.02 solid solution as 1.14 at 850 K.
Source: Journal of Magnesium and Alloys
Authors: Övgü Ceyda Yelgel, Celal Yelgel
Institutions: Recep Tayyip Erdoğan University, University of Manchester
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,500
OpenAlex ID: W2964584730