Speaker
Description
Rare-earth nickelates, RNiO$_{3}$, represent an intriguing example of materials with a highly tunable metal-insulator transition (MIT) and high potential for heterostructure engineering. The $T$-dependent paramagnetic MIT observed both in the bulk and ultrathin films of RNiO$_{3}$ is almost always accompanied by a subtle crystal-structure transformation, resulting in disproportionation of Ni-O bonds. We employ recent advances in understanding the nature of the insulating phase in RNiO$_{3}$ to unravel the mechanism underlying the combined structural/metal-insulator transition. By explicitly including lattice degrees of freedom into the description we show how a peculiar electronic structure may result in stabilization of the bond-disproportionated phase and we identify two control parameters associated with the transition.
