Abstract:
Cobalt oxide (CoO) has been widely studied due to its many advantages,
such as starting material for the manufacture of other chemicals and catalysts,
in pigments such as color reagents and in ceramics, a ground-coat
frit, promotes the adherence of enamel to steel and also used as a blue coloring
agent for pottery, enamel and glass. In this thesis the structural and
electronic properties of Cobalt mono-Oxide (CoO) were investigated using
density functional theory with Hubbard correction (DFT+U) using Quantum
Espresso package. Our study is based on DFT+U with the Perdew-
Burke-Ernzerhof (PBE)+U exchange-correlation functional, Vanderbilt (ultra
soft) pseudo-potentials and the plane wave basis set implemented in the
Quantum-ESPRESSO package. The calculation of the total minimum energy
were calculated as a function of cutoff energy and K-points sampling. The
total minimum energy per cell is monotonically decreasing with increasing
cutoff energy due to variational principle. However, this trend can not be
predicted from increasing the k-points sampling. Moreover, the equilibrium
lattice constant is calculated using results obtained from energy convergence
test (i.e; 40 Ry and 5 × 5 × 5). The computational value of the equilibrium
lattice constant is 4.24˚A. This result is in good agreement with experimental
value which is 4.27˚A. Finally, discussing band structure (with calculated
band-gap=2.45 eV) and density of state of CoO, the electrical property of
CoO is determined based on energy band gap.
