2000 character limit reached
Doping induced spin state transition in Li$_x$CoO$_2$ as studied by the GGA+DMFT calculations (1608.01475v1)
Published 4 Aug 2016 in cond-mat.str-el
Abstract: Magnetic properties of Li$x$CoO$_2$ for $x = 0.94, 0.75, 0.66$ and $0.51$ were investigated in frames of method combining Generalized Gradient Approximation with Dynamical Mean--Field Theory (GGA+DMFT). We found that a delicate interplay between Hund's exchange energy and $t{2g}-e_g$ crystal field splitting is responsible for the high spin to low spin state transition for Co${4+}$ ions. The GGA+DMFT calculations show that at small doping level the Co${4+}$ ions adopt high spin state, while delithiation results in increase of the crystal field splitting and low spin state becomes preferable. The Co${3+}$ ions were found to stays in the low spin configuration for any $x$.