Abstract:
This research article explores the comprehensive characterization of Mg8Si4 and Sr2Mg6Si8 systems,
delving into their structural, electrical, dynamical, optical, and thermoelectric properties. Employing
GGA and HSE06 hybrid functional calculations alongside semiclassical Boltzmann technique calculations,
the study reveals intriguing insights. Through examination of cohesive and formation energies, it
is established that Sr2Mg6Si8 exhibits the most stable condition. Phonon dispersion confrms the
structural stability of both compounds. Mg8Si4 possesses an indirect band gap of 0.222 eV, whereas
Sr2Mg6Si8 showcases a direct band gap of 0.752 eV under HSE06 analysis. Notably, Sr2Mg6Si8 displays
superior electrical conductivity and Seebeck coefcient despite low lattice thermal conductivity,
resulting in a promising thermoelectric fgure of merit (ZT) of 0.64 at 700 K. Moreover, the composition
Sr2Mg6Si4 exhibits a notable Power Factor of 4× 1012 WK−2 m−1 s−1 at 700 K, highlighting its potential for
thermoelectric applications.
