Fig. 2: Pressure and temperature dependences of BiNiO3 measurements.

a Temperature dependence of resistivity at high pressures, showing the partial transformation to insulating Phase-Id at 4–5 GPa. b Temperature dependence of unit cell volume on 4.3 GPa. Pressure evolution of XAS spectra around (c) Bi-L3 and (d) Ni-K edges. The red triangle, green inverted triangle and blue circle symbols indicate Phase-I, Phase-II and Phase-Id, respectively, and the pre-edge peaks are shown in the inset of each figure.