Systematic Simulations of Structural Stability, Phonon Dispersions, and Thermal Expansion in Zinc-Blende ZnO
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nanomaterials-15-00308-v2.pdf
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2.32 MB
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6b71c0df8a1f341c81ffbdec3db16aa2
Author(s)
Talwar, Devki N.
Becla, Piotr
Date Issued
February 17, 2025
Journal
Nanomaterials
Publisher
Multidisciplinary Digital Publishing Institute
Citation
Talwar, D.N.; Becla, P. Systematic Simulations of Structural Stability, Phonon Dispersions, and Thermal Expansion in Zinc-Blende ZnO. Nanomaterials 2025, 15, 308.
Version
Final published version
Abstract
Zinc oxide (ZnO) has recently gained considerable attention due to its exceptional properties, including higher electron mobility, good thermal conductivity, high breakdown voltage, and a relatively large exciton-binding energy. These characteristics helped engineers to develop low dimensional heterostructures (LDHs)-based advanced flexible/transparent nanoelectronics, which were then integrated into thermal management systems. Coefficients of thermal expansion α(T),
phonon dispersions ωj(q→)
, and Grüneisen parameters γj(q→)
can play important roles in evaluating the suitability of materials in such devices. By adopting a realistic rigid-ion model in the quasi-harmonic approximation, this work aims to report the results of a methodical study to comprehend the structural, lattice dynamical, and thermodynamic behavior of zinc-blende (zb) ZnO. Systematic calculations of ωj(q→)
, γj(q→),
and α(T)
have indicated negative thermal expansion (NTE) at low T. Soft transverse acoustic shear mode gammas γTA
at critical points offered major contributions to NTE. Our results of ωj(q→)
at ambient pressure compare reasonably well with Raman scattering spectroscopy measurements and first-principles calculations. By adjusting the layers of materials with positive and negative thermal expansion, it is possible to create LDHs with near-zero α(T)
. Such a nanostructure might experience a minimal dimensional change with T fluctuations, making it ideal for devices where precise dimensional stability is crucial.
MIT Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering
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DOI of Published Version
https://doi.org/10.3390/nano15040308
