Figure 1

(Color online). $E\left(V\right)$ curves for the BFO phases here considered (see text). Inset: structure of the ferroelectric $R3c$ phase of BFO stable at ambient conditions.Reuse & Permissions

Figure 2

(Color online). Pressure dependence of the (a) enthalpy, (b) volume, (c) Fe’s magnetic moment, (d) and electronic band gap of the HS, LS, and NS phases of BFO (see text). We give the results for all three phases in the whole pressure range, but note that each phase is stable only within one particular interval and metastable at other pressures. Dashed vertical lines mark the computed transition pressures. Panel (a): We take as the zero of enthalpy the pressure-dependent result for the HS phase. Panel (d): The highlighted area is suggestive of the subtleties pertaining to the value of $E_{\text{gap}}$ in the LS phase (see text).Reuse & Permissions

Figure 3

(Color online). Pressure dependence of the structure of the HS, LS, and NS phases of BFO (see text). Shown are (a) the lattice parameter of the ten-atom unit cell, (b) the rhombohedral angle, and (c–e) the parameters associated to the occupied Wyckoff orbits as defined in Table . We give the results for all three phases in the whole pressure range, but note that each phase is stable only within one particular interval and metastable at other pressures. Dashed vertical lines mark the computed transition pressures.Reuse & Permissions

Figure 4

(Color online). Left: surroundings of Bi in the BFO structure. The six nearest-neighboring oxygen atoms are split in two groups, denoted O(1) and O(2) and colored differently, each of which is composed of three symmetry-related atoms that form a plane perpendicular to the [111] direction. Right: Structural parameters relevant to the HS-LS transition.Reuse & Permissions

Figure 5

(Color online). Electronic density of states of the FM and AFM configurations of the LS phase of BFO at 50 GPa. The shaded area indicates the result for one ${\text{Fe}}^{3+}$ ion with its local magnetic moment pointing up.Reuse & Permissions