The role of various permutations of TiO2 and MoS2 nanolayers on the radiation tolerance of Cu-TMD and Cu-TMO nanocomposites

Abstract

Cu-based nanocomposites (NCs) are expected to have high radiation tolerance. Here we focus on using titanium dioxide (TiO2) and molybdenum disulphide (MoS2) to investigate interactions of interface of Cu- transition metal dilucogenides (TMD) and Cu- transition metal oxide (TMO) NCs which have been called Cu-2D material NCs. We generate six configurations of NCs including Cu/ TiO2/Cu (Sample1), Cu/TiO2@Cu@TiO2/Cu (Sample2), Cu/TiO2@Cu@MoS2/Cu (Sample3), Cu/MoS2@Cu@TiO2/Cu (Sample4), Cu/MoS2@Cu@MoS2/Cu (Sample5), and Cu/ MoS2TiO2/Cu (Sample6) to suggest the best model for improving the radiation tolerance of Cu-2D material NCs. The irradiation tolerance simulations have been carried out under a collision cascade induced by 6 keV primary knock-on atom (PKA) by atomistic simulations. Results imply the radiation tolerance of the Sample4 and Sample5 NCs is higher than that of other studied NCs. In order to clarify the sink action of the interface of these two NCs, we evaluated radiation defects and thermodynamics properties of this region at 3, 6, and 9 keV PKA energy. The dissipated potential energy in Cu layers of the Sample4 interface is significantly higher than that of Sample5 interface for 6 and 9 keV of PKA energy. The results of energetic calculations indicate the defect formation energy is reduced in the vicinity of interfaces. Compared with the Sample4, the Sample5 has low segregation energy for the interstitial emission mechanism to annihilate vacancies. Also, the interface of Sample5 has a higher strength of interaction and attraction with vacancies due to the low value of vacancy formation energy (Evac).