Fig. 6: Equation of state fit, and electronic and total energy for bulk NdNiO3 and layered NdNiO3/NdAlO3 structures.
From: Quantifying the role of the lattice in metal–insulator phase transitions
a Data showing electronic disproportionation as a function of structural distortion ΔN(Q), from4 (points) and the polynomials (light lines) obtained by fitting the data to the equation of state, Eq. 7. b Electronic and c total energy as functions of electronic order parameter ΔN for bulk NdNiO3 and for superlattices consisting of a bilayer of NdNiO3 alternating with NdAlO3 and a monolayer of NdNiO3 alternating with three layers of NdAlO3 using data from ref. 4. d Total energy as function of octahedral distortion Q after minimizing over electronic disproportionation ΔN. Note change of y-axis scale between panel a and other two panels. Energy normalized to correspond to 10 atom unit cell for the bulk, and per two Ni atoms (one layer) of NdNiO3 in the superlattices.
