Affiliation:
1. School of Physics and Electronics, Hunan Key Laboratory of Super Microstructure and Ultrafast Process, Hunan Key Laboratory of Nanophotonics and Devices, State Key Laboratory of Powder Metallurgy, Central South University , Changsha 410083, China
Abstract
Using the ab initio-based training database, we trained the potential function for ammonium iodide (NH4I) based on a deep neural network-based model. On the basis of this potential function, we simulated the temperature-driven β ⇒ α-phase transition of NH4I with isobaric isothermal ensemble via molecular dynamics simulations, the results of which are in good agreement with recent experimental results. As it increases near the phase transition temperature, a quarter of ionic bonds of NH4+-I− break so that NH4+ starts to rotate randomly in a disorderly manner, being able to store thermal energy without a temperature rise. It is found that NH4I possesses a giant isothermal entropy change (∼93 J K−1 kg−1) and adiabatic temperature (∼27 K) at low driving pressure (∼10 MPa). In addition, through partial substitution of I by Br in NH4I, it is found that the thermal conductivity can be remarkably improved, ascribed to the enhancement of lifetime of low frequency phonons contributed by bromine and iodine. The present work provides a method and important guidance for the future exploration and design of barocaloric material for practical applications.
Funder
National Natural Science Foundation of China
Scientific Research Innovation Project of Hunan Postgraduate
Subject
Physics and Astronomy (miscellaneous)
Cited by
5 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献