Molecular Dynamics Simulation And Experimental Research On Thermal Conductivity Of VO₂ Thin Film

Vanadium dioxide?VO₂?is an excellent phase change material.The metal-insulator phase transition?MIT?temperature of this material is closest to room temperature.With the change of crystal phase,many properties have changed.The phase change material working at the transition point of its crystal phase structure may potentially generate a heat path to effectively conduct heat to the outside of the material and make it work at the optimal temperature.Therefore,it is very necessary to conduct research on the thermal conductivity of VO2 thin film materials near the phase transition temperature range.In this paper,the magnetron sputtering method is used to prepare VO₂ thin film samples,and the preparation parameters are summarized.the thermal conductivity of the VO2 thin film material was tested at room temperature using a transient heat reflection system.The test results of the experiment show that:in the range of 60-200nm,the total thermal resistance of the VO₂ film increases linearly with the increase of the film thickness,and there is basically no relationship between the film thermal conductivity and the thickness.The thermal conductivity is 3.61W/mK.In this paper,molecular dynamics simulation is used to study the thermal conductivity of VO₂ thin film.The simulation results show that the thermal conductivity of the monoclinic phase crystal structure VO₂ thin film decreases with increasing temperature from 310K-340K,from 4.073 W/mK to 3.173W/mK;the rutile phase crystal structure VO₂ film is 350K The thermal conductivity in the-380K temperature range also decreases with increasing temperature,from 4.801 W/mK to 4.206 W/mK;while in the phase transition temperature range of 340K-350K,the thermal conductivity is changed from the monoclinic phase crystal structure 3.173W/mK,which jumped to 4.801 W/mK in the rutile phase,with a roughly 50%increase.At the same time,based on the Bruggeman symmetry model of effective medium theory,the phase change model of VO2 thermal conductivity is established,and the change of thermal conductivity in the phase transition temperature range is studied.In this paper,through experimental testing and simulation,the thermal characteristics of VO₂ thin film are studied,especially the change of thermal conductivity of VO₂ thin film near the phase transition temperature range,which has an important reference value for the thermal management of electronic devices and makes related electronic devices stable effective work.