Magnetic MXenes: From Theoretical Predictions Toward Experimental Validation-Mechanisms, Characterization, and Emerging Applications.

MXenes, a rapidly expanding family of two-dimensional transition metal carbides, nitrides, and carbonitrides, have attracted considerable attention owing to their highly tunable electronic, mechanical, and chemical properties. Their magnetic behavior, governed by composition, surface terminations, defects, doping, strain, and heterostructure engineering, has positioned them as promising candidates for spintronics, magnetic sensing, microwave absorption, and quantum technologies. This review critically examines both theoretically predicted and experimentally observed magnetic phenomena in MXenes, with particular emphasis on distinguishing intrinsic lattice magnetism from magnetism induced by interfaces, surface chemistry, defects, and contamination. We systematically discuss the influence of transition-metal chemistry, surface functionalization, and external stimuli on magnetic ordering, while evaluating density functional theory predictions alongside available experimental evidence and advanced magnetic characterization techniques. Unlike previous reviews, this work focuses on the persistent gap between computational predictions and reproducible experimental observations, highlighting the limited experimental verification of intrinsic magnetic order in MXenes. Current evidence indicates that most reported magnetic responses arise from extrinsic effects rather than robust intrinsic lattice magnetism. By identifying the key factors limiting reproducibility and proposing priorities for future experimental validation, this review provides a critical framework for the rational development of magnetic MXenes and their future device applications.