Seminarium Fizyki Ciała Stałego

Secondary Ion Mass Spectrometry (SIMS) has long been known for its unparalleled sensitivity, yet its full potential for 2D materials remained largely untapped - until now. We have developed a groundbreaking SIMS methodology that enables true atomic-layer precision in depth profiling of MXenes and MAX phases, overcoming the notorious mixing effect that has hindered previous studies. By decreasing the primary ion impact energy to ultralow levels, increasing incidence angle, optimizing extraction parameters, and developing an in situ sample preparation phase called ion polishing, we have achieved a level of resolution previously deemed impossible for small, layered particles.This novel approach has led to several breakthroughs. We provide direct evidence of oxygen incorporation within the X sublattice of MXenes, identifying distinct oxycarbide, oxynitride, and oxycarbonitride subclasses. Furthermore, we unravel subtle compositional variations in surface terminations and transition metal ordering, revealing critical structural insights that impact electronic and catalytic properties. Our method enables layer-by-layer analysis even in cases where a single atomic layer contains up to thirteen different transition metals, pushing the boundaries of materials characterization.Additionally, this technique allows for the direct detection of hydrogen within samples, achieving sub-layer resolution. Hydrogen can be precisely located between the atomic layers of the investigated materials, providing unique insights into its distribution and interactions at the nanoscale.With atomic-scale resolution on micrometer-sized flakes, our work pushes SIMS beyond traditional limitations, offering a powerful tool for characterizing next-generation 2D materials. This advancement provides unprecedented insights into the chemistry and structure of complex layered systems, establishing SIMS as an indispensable technique for studying MXenes and related materials.