Stability of Ti–Zr–N coatings under Xe-ion irradiation

Abstract

Titanium nitride is a technological important refractory material combining the physical properties of ceramics and metal. In addition to its wide use as protective hard coating for cutting tools or metallization layer in microelectronics, it is one of the inert matrixes proposed to surround the fuel in future gas cooled fast reactor (GFR) systems. The application of low-dose inert gas ions in materials is a powerful method for studying material properties changes due to irradiation damage. In this work, the influence of Xe-ion irradiation on the structure, electrical and mechanical properties of ternary TiN-based coating is investigated. Ti x Zr 1 − x N ( x = 0, 0.25, 0.50, 0.75, 1) thin films (∼ 300 nm thickness) were deposited on (100) Si substrate using unbalanced reactive magnetron co-sputtering. Irradiation with Xe ( q = + 18) ions were carried out at fluence of 8 · 10 14 ions cm − 2 and energy of 360 keV. The morphology, phase and element compositions of the as-grown and irradiated samples were studied using SEM, XRD and RBS. It is found that the simultaneous sputtering of metal targets in Ar/N 2 atmosphere leads to formation of ternary solid solution nitrides with Na–Cl structure with enhanced hardness compared to binary counterpart while the nanohardness decreases for binary nitrides after ion irradiation and increase is observed for ternary nitrides. A detailed analysis of elastic strains and stresses changes after ion irradiation is also performed.