What question did this study set out to answer?

To explore the structural, electronic, mechanical, and thermoelectric properties of LaLiX half-Heusler compounds using density functional theory.

March 8, 2026

Ab initio investigation of structural, electronic, mechanical, thermoelectric, and optical properties of laLiX (X = Si, ge) half-Heusler compounds

Key Points

To explore the structural, electronic, mechanical, and thermoelectric properties of LaLiX half-Heusler compounds using density functional theory.
Ab initio density functional theory calculations
Formation energy evaluations for thermodynamic stability
Mechanical stability assessments using ductility metrics
Electronic structure analysis for band gap determination
Boltzmann transport calculations for thermoelectric performance
LaLiSi and LaLiGe show indirect band gaps of 0.42 eV and 0.48 eV, indicating semiconductor behavior.
Strong optical absorption suggests potential for optoelectronic applications.
Mechanical stability confirmed through Pugh’s ratio and Cauchy pressure metrics.
Promising thermoelectric performance with near-unity ZT at room temperature.

Abstract

We present the first ab initio density functional theory study of 8-valence electron LaLiX (X = Si, Ge) half-Heusler compounds, investigating their structural, mechanical, electronic, phonon, thermoelectric, and optical properties. Formation energy calculations confirm thermodynamic stability, while Born–Huang criteria and ductility metrics (Pugh’s ratio, Cauchy pressure) reveal mechanical stability and deformability. Electronic structure calculations show indirect band gaps of 0.42 eV (LaLiSi) and 0.48 eV (LaLiGe), suggesting semiconductor behavior. Strong optical absorption in the visible region highlights optoelectronic potential. Boltzmann transport calculations predict promising thermoelectric performance, with near-unity figure of merit (ZT) at room temperature, indicating viability for energy conversion. These findings position LaLiSi and LaLiGe as novel multifunctional materials for optoelectronics and thermoelectric applications.

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Ab initio investigation of structural, electronic, mechanical, thermoelectric, and optical properties of laLiX (X = Si, ge) half-Heusler compounds

Key Points

Abstract

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