Figure 4

STEM images of SFT in NiFe irradiated by 3 MeV Au ions to 5 × 10¹⁵/cm².

(a) BF STEM image showing SFTs either distributed separately (blue circle) or coupled to form parallelograms (red circle); (b) High-resolution HAADF image showing a parallelogram made by two SFTs. The images were taken with the electron beam direction parallel to [100].