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Bibliographic Details
Main Authors: Abdullaev, Azat, Sekerbayev, Kairolla, Azarov, Alexander, Venkatachalapathy, Vishnukanthan, Chauhan, Vinay S., Utegulov, Zhandos, Kuznetsov, Andrej
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2406.03767
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author Abdullaev, Azat
Sekerbayev, Kairolla
Azarov, Alexander
Venkatachalapathy, Vishnukanthan
Chauhan, Vinay S.
Utegulov, Zhandos
Kuznetsov, Andrej
author_facet Abdullaev, Azat
Sekerbayev, Kairolla
Azarov, Alexander
Venkatachalapathy, Vishnukanthan
Chauhan, Vinay S.
Utegulov, Zhandos
Kuznetsov, Andrej
contents Recently discovered double gamma/beta (γ/\b{eta}) polymorph Ga2O3 structures constitute a class of novel materials providing an option to modulate functional properties across interfaces without changing chemical compositions of materials, in contrast to that in conventional heterostructures. In this work, for the first time, we investigate thermal transport in such homo-interface structures as an example of their physical properties. Specifically, the cross-plane thermal conductivity (k) was measured by femtosecond laser-based time-domain thermoreflectance with MHz modulation rates, effectively obtaining depth profiles of the thermal conductivity across the γ/\b{eta}-Ga2O3 structures. In this way, the thermal conductivity of γ-Ga2O3 k=1.84÷2.11 W m-1K-1 was found to be independent of the initial \b{eta}-substrates orientations, in accordance with the cubic spinel structure of the γ-phase and consistently with the molecular dynamics simulation data. In its turn, the thermal conductivity of monoclinic \b{eta}-Ga2O3 showed a distinct anisotropy, with values ranging from 10 W m-1K-1 for [201] to 20 Wm-1K-1 for [010] orientations. Thus, for double γ/\b{eta} Ga2O3 polymorph structures formed on [010] \b{eta}-substrates, there is an order of magnitude difference in thermal conductivity across the γ/\b{eta} interface, which potentially can be exploited in thermal energy conversion applications.
format Preprint
id arxiv_https___arxiv_org_abs_2406_03767
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Thermal Conductivity of Double Polymorph Ga2O3 Structures
Abdullaev, Azat
Sekerbayev, Kairolla
Azarov, Alexander
Venkatachalapathy, Vishnukanthan
Chauhan, Vinay S.
Utegulov, Zhandos
Kuznetsov, Andrej
Materials Science
Recently discovered double gamma/beta (γ/\b{eta}) polymorph Ga2O3 structures constitute a class of novel materials providing an option to modulate functional properties across interfaces without changing chemical compositions of materials, in contrast to that in conventional heterostructures. In this work, for the first time, we investigate thermal transport in such homo-interface structures as an example of their physical properties. Specifically, the cross-plane thermal conductivity (k) was measured by femtosecond laser-based time-domain thermoreflectance with MHz modulation rates, effectively obtaining depth profiles of the thermal conductivity across the γ/\b{eta}-Ga2O3 structures. In this way, the thermal conductivity of γ-Ga2O3 k=1.84÷2.11 W m-1K-1 was found to be independent of the initial \b{eta}-substrates orientations, in accordance with the cubic spinel structure of the γ-phase and consistently with the molecular dynamics simulation data. In its turn, the thermal conductivity of monoclinic \b{eta}-Ga2O3 showed a distinct anisotropy, with values ranging from 10 W m-1K-1 for [201] to 20 Wm-1K-1 for [010] orientations. Thus, for double γ/\b{eta} Ga2O3 polymorph structures formed on [010] \b{eta}-substrates, there is an order of magnitude difference in thermal conductivity across the γ/\b{eta} interface, which potentially can be exploited in thermal energy conversion applications.
title Thermal Conductivity of Double Polymorph Ga2O3 Structures
topic Materials Science
url https://arxiv.org/abs/2406.03767