Campus Units

Materials Science and Engineering, Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

6-22-2020

Journal or Book Title

Applied Physics Letters

Volume

116

Issue

25

First Page

251901

DOI

10.1063/5.0012166

Abstract

Elastocaloric cooling utilizes the latent heat associated with stress-induced reversible phase transformations to achieve cooling. Currently, the key barrier to this technology is its prohibitive cost due to the high elastocaloric material cost and the large stress required to drive the cooling cycle. Vanadium (IV) oxide (VO2) is a good candidate, and it is relatively cheap. Our calorimetry study shows it exhibits a reversible phase transformation with a large latent heat of 31.5 J/g as well as excellent functional stability. Its transformation temperature and latent heat are tunable via heat treatment. We demonstrate that VO2 powders can be cyclically compressed in a steel tube using a steel plunger to drive the elastocaloric effect. The application of relatively low stress of 300 MPa is sufficient to result in a reversible temperature change of 0.5 degrees C on the powder compact. Further improvement of reversible temperature change to 1.6 degrees C under 300 MPa is achieved by adding conductive copper powders. Future efforts should focus on improving material properties such as heat capacity and thermal conductivity for candidate ceramic oxides to maximize elastocaloric effects.

Comments

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Ouyang, Gaoyuan, Chaochao Pan, Sam Wolf, Pratyasha Mohapatra, Ichiro Takeuchi, and Jun Cui. "Elastocaloric effect in vanadium (IV) oxide." Applied Physics Letters 116, no. 25 (2020): 251901, and may be found at DOI: 10.1063/5.0012166. Posted with permission.

Copyright Owner

AIP Publishing, LLC

Language

en

File Format

application/pdf

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