Fig. 4 shows the calculated results of the total and partial
density of states(DOS) of Ba2CeCoO6. It is clear that the reisan
energy gap at the Fermilevel in the spin-upstates,while the spin-
down states are metallic. The energy gap in the spin-upbandand
metallicity in the spin-downband cause100% spin polarization at
the Fermilevel. Non-zerospin flip gap proves that this compound
is a true half-metallic ferromagnet. It can be seen that the total
DOS are mainly contributed by Co-3d and O-2p electrons in the
energy range of 3.0 eV to Fermilevel. Above the Fermilevel,the
Ba-5d states make a main contribution to the total DOS. Con-
sidering the peaks near the Fermilevel, we find that the presence
of an octahedral crystal field of the six oxygen atoms around the
Co site results in a splitting of the five-fold degenerate Co-3d states
into doubly degenerateeg (dz2 and dx2 y2 ) states with higher
energy and triply degenerate t2g (dxy, dyz and dzx ) states with
lower energy for both spin-up and spin-down channels. The spin-
splitting of about0.63eV makes the spin-down states of the triply
degenerate t2g cross the Fermilevel, resulting in the partial
occupation, and spin-up t2g states are occupied and lieat about
0.49eV under the Fermilevel. Both the eg states of spin-down
and spin-up lying respectively at about 2.0 and 2.1eV are not
occupied.
The calculated values of the total and partial magnetic moment
of this compoundare listed in Table2. The value of the total
magnetic moments is predicted to be 1.0 μB . For this compound,
the main contribution to the total magnetic moment comes from
the Co and O atoms, while the contributions of Ba and Ce atoms
are very small.