Fig. 3
From: Domain imaging across the magneto-structural phase transitions in Fe1+yTe
Structural models of Fe1+yTe in the \({\cal T}\) and \({\cal M}\) phases. a, b Simplified unit cell models for the \({\cal T}\) phase (a) and for the \({\cal M}\) phase (b) with the indicated directions of the a, b, and c lattice vectors and the corresponding angles. c Illustration of the proposed structural model for the \({\cal M}\) phase of Fe1.08Te with four rotational domains composed of unit cells which are rotated by 0° (yellow), 180° (red), θ (blue), and θ + 180° (green). Vectors in the direction of a (red), and b (blue), as well as the definition of the angles β and δ are indicated. d, e Top views of the A-type (d) and B-type (e) structural domain boundaries (same domain colors, vectors and angles as in c). f Constant-current STM image of the surface of Fe1.08Te below TN overlayed with a color map marking the four rotational structural domains with the same colors as in c (Vs = 300 mV, It = 40 pA, scale bar width 200 nm, color scale from 0 (black) to 3.2 nm (white)). The dashed yellow and blue lines mark the A- and B-type boundaries, respectively. The angle θ between A-type boundaries is indicated. g, h Profiles perpendicular across two B-type (g) and two A-type (h) boundaries. The profiles were taken along the lines which are marked with the identical colors in f. The extracted angles δ and β are indicated
