LDA+DMFT study of magnetic transition and metallization in CoO under pressure
A. A. Dyachenko+, A. O. Shorikov+*, A. V. Lukoyanov+*, V. I. Anisimov+*
+Institute of Metal Physics UB RAS, 620990 Ekaterinburg, Russia
*Ural Federal University, 620002 Ekaterinburg, Russia
Abstract
In this work we report results of magnetic and spectral properties
calculation for paramagnetic phase of CoO at ambient and high pressures
performed within the LDA+DMFT method combining local density approximation
(LDA) with dynamical mean-field theory (DMFT). From our results CoO at
ambient pressure is a charge transfer insulator in the high-spin
t52ge2g configuration. The energy gap is continuously
decreased, and finally a transition into metallic state occurs with the
increase of pressure that is consistent with experimental behavior of
electrical resistivity. Notably, the metal-insulator transition in CoO is
found to be accompanied
by the high-spin to low-spin (HS-LS) transition in agreement with XES data.
The metal-insulator transition is orbital selective in the t2g states
of cobalt only, whereas the eg states become metallic after the spin
transition at higher pressures.