Fig. 1: Structural configurations and energy map.
From: Intrinsic multiferroicity in molybdenum oxytrihalides nanowires
a The side view of MoOBr3 bulk phase, where Mo atoms show as green balls, O atoms show as red balls and Br atoms show as brown balls. The periodic direction of MoOBr3 nanowires is along ‘a’ direction, and the dash line shows one unit bulk cell. b The three-dimensional (3D) view (top panel), top view (middle panel) and front view (bottom panel) of a single MoOBr3 nanowire, and dash line indicates one unit cell in which two Mo atoms are named Mo1 and Mo2, respectively. c Top views of two energy degenerate Mo-displaced polar structures with opposite polarization (phases A and A’), two energy degenerate Mo-displaced nonpolar structures without polarization (phases B and B’) and Mo-nondisplaced centrosymmetric structure (phase C). d The free energy contour plot of single MoOBr3 nanowires as a function of displacement of Mo1 (d1) and displacement of Mo2 (d2). The positions of phases A’, A, B, B’ and C are indicated on the contour plot.
