H. Nakatsugawa et E. Iguchi, Study of electronic structures in LaCo1-xTixO3 (x=0,0.05 and 0.15) using discrete-variational-X alpha cluster method, JPN J A P 1, 39(3A), 2000, pp. 1186-1189
Electronic structures of [CoO6](9-) clusters have been studied by ab initio
molecular-orbital (MO) calculations using the discrete-variational (DV)-X
alpha cluster method in order to investigate the correlation between the ch
ange in the type of the majority carrier and electronic structures in LaCo1
-xTixO3 (x = 0, 0.05 and 0.15). The most significant features are that the
e(g up arrow) bandwidth in the x not equal 0 specimen is wide in comparison
with the x = 0 specimen and the Co-O bonding MO energy levels in the x not
equal 0 specimens are in the energy range of -3 eV to -2 eV. These calcula
tions indicate that both the 3d electrons in donor centers of sigma* bands
and the O 2p ligand holes in sigma* bands are responsible for the electroni
c conduction in the x = 0.05 and x = 0.15 specimens but the competition bet
ween the densities of 3d electrons in sigma* bands and O 2p ligand holes do
minates the type of the majority carrier.