The structural, elastic, electronic, magnetic, and thermoelectric properties of
MgEu2X4 (X ¼ S and Se) spinel compounds are investigated computationally.
Calculations are performed using the full-potential linearized augmented plane
wave (FP-LAPW) method within the Perdew, Burke, and Ernzerhof generalized
gradient approximation (PBE-GGA), GGA þ U, and modified Becke–Johnson
(mBJ-GGA) approximations. The band structure and density of states results
from the three exchange-correlation approximation methods (mBJ, GGA þ U,
and PBE) show that these spinel compounds are fully spin-polarized. Also, they
possess a half-metallic character in the spin-down channel with a direct bandgap
(Γ–Γ) of about 3.44, 2.712, and 2.472 eV for MgEu2S4 and 2.89, 2.285, and
2.017 eV for MgEu2Se4, respectively. The formation of both compounds is
energetically favorable based on the results of the total energy and cohesive
energy calculations. Furthermore, the two compounds are chemically and
mechanically stable, as concluded from cohesive energy and elastic calculations.
The elastic calculations reveal that both spinel compounds are ductile materials.
The ionic bonds are predominant. The quasi-harmonic model has also been used
to investigate the influences of temperature and pressure on thermal characteristics.
The thermoelectric behavior is studied using the BoltzTraP code. Both
systems show good thermoelectric properties for the spin-down channel.

Title

PHYSICA STATUS SOLIDI B - BASIC SOLID STATE PHYSICS

Publisher

WILEY-V C H VERLAG GMBH

Publisher Country

Germany

Indexing

Thomson Reuters

Impact Factor

1.782

Publication Type

Both (Printed and Online)

Volume

259

Year

2022

Pages

14