Giant Exfoliation Induced Magnetic Coercivity in Fe ₃ GaTe ₂

ABSTRACT Permanent magnets with strong anisotropy and high coercivity underpin modern information and energy technologies, yet rare‐earth‐free alternatives remain limited. Here, we show that thickness engineering via mechanical exfoliation induces hard magnetic behavior in the van der Waals ferromagnet Fe 3 GaTe 2 . Bulk crystals exhibit Curie temperatures above 350 K but negligible room‐temperature coercivity. When thinned below ∼100 nm, the coercive field is dramatically enhanced, reaching nearly 1 T at room temperature for in‐plane fields—comparable to conventional hard magnets. Micromagnetic analysis reveals a crossover in magnetization reversal from domain‐mediated processes in bulk samples to quasi‐coherent rotation in thin flakes, driven by increased effective anisotropy and suppressed domain formation. This thickness‐dependent transition enables tuning of magnetic hardness without chemical modification. Combined with high saturation magnetization and robust room‐temperature performance, Fe 3 GaTe 2 emerges as a promising rare‐earth‐free material for spintronic applications. Its layered structure further allows integration into van der Waals heterostructures, where large in‐plane coercivity can stabilize magnetic states against perturbations and interlayer coupling, offering potential for high‐density nonvolatile memory and domain‐wall‐based devices.