Theoretical study on electric structure and ferroelectric property of PbTiO3 nanocrystals

Quantum chemistry calculations of PbTiO3 nanocrystals were carried out by m eans of the cluster model via DFT-DVM calculating program on which the regu larity among the bond lengths, bond orders, and valance charges are drawn. The analyses of the population and the density of state (DOS) show that the interaction among 3d of Ti, 2p of O, and 6s and 6p of Pb atomic orbitals c auses the dipole moment and spontaneous polarization on the axis of the cry stal, which results in the appearance of ferroelectric phase, the dipole mo ment and the intensity of the spontaneous polarization were calculated as w ell.