Особенности аннигиляции позитронов в наноразмерных металлических слоях Zr/Nb после облучения протонами

Abstract

Radiation damage limits the operating time of many structural materials under extreme conditions. Nanoscale multilayer coatings (NMCs) are a promising direction in developing materials that resist radiation damage and have improved physical and mechanical properties. This paper aims to experimentally understand changes in the defect structure of nanoscale multilayer coatings (NMCs) with alternating layers of Zr and Nb under irradiation. Zr/Nb NMCs with varying thicknesses of individual layers were fabricated using magnetron sputtering and then exposed to H+ irradiation. The evolution of the defect state under proton irradiation was studied using positron annihilation spectroscopy (PAS). The structural defects were analyzed using Doppler broadening spectroscopy (DBS) with a variable-energy positron beam. Irradiation causes destruction of interfaces when the thickness of individual layers is less than 25 nm. However, there is no significant increase in the defect level. The S parameter (amount of open volume defects) before and after irradiation remains practically unchanged. After irradiating NMC Zr/Nb with 50 and 100 nm thick layers, the microstructure remains unchanged and the S parameter is significantly reduced