Title
Measurement of the hysteretic thermal properties of W-doped and undoped nanocrystalline powders of VO<inf>2</inf>
Date Issued
01 December 2019
Access level
open access
Resource Type
journal article
Author(s)
Gomez-Heredia C.L.
Ramirez-Rincon J.A.
Bhardwaj D.
Rajasekar P.
Tadeo I.J.
Cervantes-Lopez J.L.
Ares O.
Umarji A.M.
Drevillon J.
Joulain K.
Ezzahri Y.
Alvarado-Gil J.J.
Université de Poitiers
Publisher(s)
Nature Publishing Group
Abstract
Hysteresis loops exhibited by the thermal properties of undoped and 0.8 at.% W-doped nanocrystalline powders of VO2 synthesized by means of the solution combustion method and compacted in pellets, are experimentally measured by photothermal radiometry. It is shown that: (i) the W doping reduces both the hysteresis loops of VO2 and its transition temperature up to 15 °C. (ii) The thermal diffusivity decreases (increases) until (after) the metallic domains become dominant in the VO2 insulating matrix, such that its variation across the metal-insulation transition is enhanced by 23.5% with W-0.8 at.% doping. By contrast, thermal conductivity (thermal effusivity) increases up to 45% (40%) as the metallic phase emerges in the VO2 structure due to the insulator-to-metal transition, and it enhances up to 11% (25%) in the insulator state when the local rutile phase is induced by the tungsten doping. (iii) The characteristic peak of the VO2 specific heat capacity is observed in both heating and cooling processes, such that the phase transition of the 0.8 at.% W-doped sample requires about 24% less thermal energy than the undoped one. (iv) The impact of the W doping on the four above-mentioned thermal properties of VO2 mainly shows up in its insulator phase, as a result of the distortion of the local lattice induced by the electrons of tungsten. W doping at 0.8 at.% thus enhances the VO2 capability to transport heat but diminishes its thermal switching efficiency.
Volume
9
Issue
1
Language
English
OCDE Knowledge area
Nano-procesos
Nano-materiales
Scopus EID
2-s2.0-85073168348
PubMed ID
Source
Scientific Reports
Sponsor(s)
This work has been partially supported by the Projects 192 “Fronteras de la ciencia”, 251882 “Investigación Científica Básica 2015” and the Cellule Énergie du CNRS through the grant N° 267745. C.L. Gomez-Heredia and J.A. Ramirez-Rincon thank Conacyt for their PhD scholarships. C.L. Gomez-Heredia acknowledges the financial support for finishing her PhD from Conacyt Project 251882 “Investigación Científica Básica 2015”. Devanshi Bhardwaj would like to thank CSIR for providing fellowship. Rajasekar P. acknowledges UGC, India for Ph.D. Fellowship. I.J. Tadeo thank OIR, IISc for Ph.D. Fellowship. Authors acknowledge the technical support of M.C. Jose Bante Guerra and Dr. J.D. Macias technical assistance. SEM and DSC analyses were performed at the National Laboratory of Nano and Biomaterials (Funded by Fomix-Yucatán and Conacyt 2008–108160 Y), Cinvestav-IPN. Unidad Merida. We thank Dr. Patricia Quintana for allowing the use of LANNBIO facilities, M.C. Dora Huerta her grateful assistance in obtaining SEM images M.C. Jose Luis Cortes for his technical support in obtaining the DSC profiles. Authors would also like to thank Cense for providing access to Raman facility.
Sources of information:
Directorio de Producción Científica
Scopus