Microstructural characterization of zirconium carbide implanted with europium ions and annealed in a hydrogen atmosphere.

Abstract

This study investigates the effect of europium (Eu) ion implantation and heat treatment on the microstructure of ZrC along with the diffusion behaviour of Eu ions in the ZrC substrate. ZrC samples were implanted with Eu ions at room temperature with a fluence of 1×10¹⁶ cm⁻² and an energy of 360 keV, then annealed from 600°C to 800°C. Structural changes, elemental composition, strain, phase identification, and diffusion were analyzed using Scanning Electron Microscopy (SEM), EDS, X-ray Diffraction (XRD), and Rutherford Backscattering Spectroscopy (RBS). XRD analysis indicated implantation-induced structural damage, as evidenced by increased FWHM, suggesting lattice strain and defects. RBS revealed a europium penetration depth of ~76 nm, while annealing at 700°C caused Eu ions to migrate closer to the surface, and at 800°C, they diffused outward, with SEM showing larger surface cracks. Oxidation began at 600°C, with ZrO₂ formation confirmed by XRD and EDS, peaking at 700°C, and partially reducing at 800°C in a hydrogen-rich atmosphere. XRD data also showed recrystallization during annealing, with enhanced peak intensities and increased crystallite sizes, highlighting the interplay between Eu diffusion, surface oxidation, and microstructural recovery in ZrC.