Pressure-induced metal-insulator and spin-state transition in low-valence layered nickelates

Victor Pardo, Warren E. Pickett
2012 Physical Review B  
Ab initio calculations predict a metal-insulator transition at zero temperature to occur in La_4Ni_3O_8 at moderate pressures as a result of a pressure-induced spin-state transition. The spin-state transition that is seen at 105 K at ambient pressure from a low-temperature high-spin state to a high-temperature low-spin state has been observed to be shifted to lower temperatures as pressure is applied. From our calculations we find that a smaller unit cell volume favors the metallic low-spin
more » ... tallic low-spin state, which becomes more stable at 5 GPa. Similar physics should take place in the related compound La_3Ni_2O_6, but on a different energy scale, which may account for why the transition has not been observed in this material.
doi:10.1103/physrevb.85.045111 fatcat:6t2dbawgdjbgxou4zyxkijti6i