Atmosphere‐Dependent Laser Ablation Behavior and Graphitization of Diamond With Different Crystallographic Orientations

ABSTRACT Laser ablation is an effective technique for fabricating microstructures on diamond surfaces; however, the influence of ambient atmosphere on the ablation behavior and surface chemistry remains insufficiently understood. In this study, nanosecond laser ablation experiments were performed on single‐crystal diamond under different gaseous environments (O 2 , air, N 2 , He, and Ne). The ablation morphology, graphitization behavior, and surface chemical bonding were characterized using laser confocal microscopy, Raman spectroscopy, and X‐ray photoelectron spectroscopy (XPS). The results show that the ambient atmosphere significantly affects the ablation efficiency and surface structure. Oxidizing atmospheres (O 2 and Air) lead to higher material removal rates due to thermochemical oxidation reactions, while inert atmospheres (He and Ne) produce smoother groove edges and more uniform surfaces. Raman analysis indicates that the graphitization degree varies with atmosphere, with the intensity ratio of the D and G bands following the order N 2 > Ne > He > Air > O 2 . XPS results reveal that oxidizing atmospheres increase the content of oxygen‐containing bonds (C─O/C═O), whereas nitrogen and inert atmospheres favor the formation and accumulation of sp 2 carbon.