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Main Authors: Murari, Himanshu, Shaw, Swati, Ghosh, Subhradip
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2403.13543
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author Murari, Himanshu
Shaw, Swati
Ghosh, Subhradip
author_facet Murari, Himanshu
Shaw, Swati
Ghosh, Subhradip
contents Surface and strain engineering are among the cheaper ways to modulate structure property relations in materials. Due to their compositional flexibilities, MXenes, the family of two-dimensional materials, provide enough opportunity for surface engineering. In this work, we have explored the possibility of improving thermoelectric efficiency of MXenes through these routes. The Janus MXenes obtained by modifications of the transition metal constituents and the functional groups passivating their surfaces are considered as surface engineered materials on which bi-axial strain is applied in a systematic way. We find that in the three Janus compounds Zr$_{2}$COS, ZrHfO$_{2}$ and ZrHfCOS, tensile strain modifies the electronic and lattice thermoelectric parameters such that the thermoelectric efficiency can be maximised. A remarkable reduction in the lattice thermal conductivity due to increased anharmonicity and elevation in Seebeck coefficient are obtained by application of moderate tensile strain. With the help of first-principles electronic structure method and semi-classical Boltzmann transport theory we analyse the interplay of structural parameters, electronic and dynamical properties to understand the effects of strain and surface modifications on thermoelectric properties of these systems. Our detailed calculations and in depth analysis lead not only to the microscopic understanding of the influences of surface and strain engineering in these three systems, but also provide enough insights for adopting this approach and improve thermoelectric efficiencies in similar systems.
format Preprint
id arxiv_https___arxiv_org_abs_2403_13543
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Strain aided drastic reduction in lattice thermal conductivity and improved thermoelectric properties in Janus MXenes
Murari, Himanshu
Shaw, Swati
Ghosh, Subhradip
Materials Science
Surface and strain engineering are among the cheaper ways to modulate structure property relations in materials. Due to their compositional flexibilities, MXenes, the family of two-dimensional materials, provide enough opportunity for surface engineering. In this work, we have explored the possibility of improving thermoelectric efficiency of MXenes through these routes. The Janus MXenes obtained by modifications of the transition metal constituents and the functional groups passivating their surfaces are considered as surface engineered materials on which bi-axial strain is applied in a systematic way. We find that in the three Janus compounds Zr$_{2}$COS, ZrHfO$_{2}$ and ZrHfCOS, tensile strain modifies the electronic and lattice thermoelectric parameters such that the thermoelectric efficiency can be maximised. A remarkable reduction in the lattice thermal conductivity due to increased anharmonicity and elevation in Seebeck coefficient are obtained by application of moderate tensile strain. With the help of first-principles electronic structure method and semi-classical Boltzmann transport theory we analyse the interplay of structural parameters, electronic and dynamical properties to understand the effects of strain and surface modifications on thermoelectric properties of these systems. Our detailed calculations and in depth analysis lead not only to the microscopic understanding of the influences of surface and strain engineering in these three systems, but also provide enough insights for adopting this approach and improve thermoelectric efficiencies in similar systems.
title Strain aided drastic reduction in lattice thermal conductivity and improved thermoelectric properties in Janus MXenes
topic Materials Science
url https://arxiv.org/abs/2403.13543