Assessing half-Heusler alloys PtNbZ (Z=Al, Ga, In) via DFT: acceptability for thermoelectric applications

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid State Chemistry

Background:

• Half-Heusler alloys are promising materials for thermoelectric applications.
• Understanding the structural, elastic, and electronic properties is crucial for material design.

Purpose of the Study:

• To investigate the structural, elastic, and thermoelectric properties of PtNbZ (Z = Al, Ga, In) half-Heusler alloys.
• To evaluate their potential for thermoelectric power generation.

Main Methods:

• Utilized the generalized gradient approximation (GGA) and modified Beck-Johnson potential for electronic structure calculations.
• Optimized structural parameters to determine the ground state phase and magnetic properties.
• Calculated elastic constants, Debye temperature, and figure of merit (ZT).

Main Results:

• PtNbZ alloys crystallize in the Y1 phase with non-magnetic spin ordering, adhering to the Slater-Pauling rule.
• The alloys exhibit ductile behavior with direction-dependent sound velocities.
• Achieved high figure of merit (ZT) values of 0.59, 0.76, and 0.78 for PtNbAl, PtNbGa, and PtNbIn, respectively.

Conclusions:

• PtNbZ half-Heusler alloys are structurally stable and possess favorable elastic properties.
• The high ZT values suggest significant potential for efficient thermoelectric power generation applications.