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Focused ion beam (FIB) techniques are employed widely for nanofabrication, and processing of materials and devices. However, ion irradiation often gives rise to severe damage due to atomic displacements that cause defect formation, migration and clustering within the ion-solid interaction volume. The resulting restructuring degrades the functionality of materials, and limits the utility FIB ablation and nanofabrication techniques. Here we show that such restructuring can be inhibited by performing FIB irradiation in a hydrogen plasma environment via chemical pathways that modify defect binding energies and transport kinetics, as well as material ablation rates. The method is minimally-invasive and has the potential to greatly expand the utility of FIB nanofabrication techniques in processing of functional materials and devices.

The elastic interaction between kinks (and antikinks) within domain walls plays a pivotal role in shaping the domain structure, and their dynamics. In bulk materials, kinks interact as elastic monopoles, dependent on the distance between walls, and typically characterised by a rigid and straight domain configuration. In this work we investigate the evolution of the domain structure as the sample size decreases, by means of in-situ heating techniques on free-standing samples. A significant transformation is observed: domain walls exhibit pronounced curvature, accompanied by an increase in both domain wall and junction density. This transformation is attributed to the pronounced influence of kinks, inducing sample warping, where 'dipole dipole' interactions are dominant. Moreover, we experimentally identify a critical thickness range that delineates a cross-over between the monopolar and dipolar regimens and corroborated this by detailed atomic simulations. These findings are relevant for in-situ TEM studies and for the development of novel devices based on free-standing ferroic thin films and nanomaterials.