Fig. 1: Crystal structure, magnetism, and band calculations.
a Schematic crystal structure of Fe3Ge. The inset illustrates the setup of the x, y, and z axes relative to the a, b, and c axes, where the x and z axes are along the a and c axes, respectively, the y-axis is in the ab plane, at an angle of 30° to the b-axis. b LEED pattern of the treated Fe3Ge-(001) surface taken with an electron energy of 80 eV at room temperature. c A summary of the magnetic phase transitions as a function of temperature in Fe3Ge. d Bulk and (001)-projected BZs with the high-symmetry points. e–g DFT calculated band structures of Fe3Ge in the FM phase for the Fe moments (μFe ≈ 2.2μB) aligned along the x (e), y (f), and z (g) axis, respectively. As guided by the curved arrows, one can find the correspondence between the band calculations and the temperature axis in c. Two sets of DPs and vHSs below EF are highlighted by the black arrows. The FB regions at around −0.5 eV are marked out by the blue and red shades. As indicated by the red rectangles in e and f, the insets of which show the enlarged view of the nearly gapless (~0.5 meV) DP1 at K point in the planar FM state.
