Ions leaving no tracks

The paths of swift heavy ions are typically traceable in solids, because of confined electronic interactions along the paths, inducing what is known in literature as "ion tracks", i.e. nano-sized in cross-section cylindrical zones of modified material extending for microns in length. Such tracks readily form in materials exhibiting low thermal conductivities, in particular insulators or semiconductors, altering the homogeneity of materials. In this work, using recently discovered γ/β-Ga₂O₃ polymorph heterostructures, we show that, in contrast to the trends in many other materials, including that in β-Ga₂O₃, swift heavy ions leave no tracks in γ-Ga₂O₃. We explain this trend in terms of the fast disorder recovery, occurring because of multiple configurations in the γ-Ga₂O₃ lattice itself, so that the disorder formed by ion impacts gets rapidly erased, giving a perception of ions leaving no tracks. As such, γ-Ga₂O₃, readily integrated with β-Ga₂O₃ in polymorph heterostructures, emerges as a promising semiconductor platform for devices capable of operating in harsh radiation environments.