Nanoscale Ripples at the Surface of SrTiO ₃ Irradiated by a Broad Low‐Energy Ar ⁺ (7 keV) Ion Beam

The performance of nano‐optoelectronic and nano‐electronic devices can be significantly enhanced through the integration of well‐ordered nanoscale architectures. Ion irradiation has emerged as a powerful bottom‐up strategy for fabricating self‐organized nanostructures with precise spatial control, offering an effective route to modulate surface morphology and chemistry. We investigated the structural, morphological, and chemical evolution of ripple‐like nanostructures formed on single‐crystalline SrTiO 3 substrates via low‐energy Ar + (7 keV) irradiation at an oblique incidence. Periodic surface ripples were formed within a specific fluence window, where the ripple wavelength remained nearly constant despite a significant increase in surface roughness. Their creation was accompanied by significant structural and chemical changes with argon accumulation, strontium and oxygen depletion. Yet, post‐irradiation thermal annealing restored the material crystallinity while preserving the ripple morphology. These findings highlight the potential of ion‐beam engineering for creating functional oxide templates with adjustable chemical and structural properties.