Theoretical Study of La , Ca modified and Pure PbTiO_3 Nanocrystals

查看全文 作　　者：FU Hong gang a,b * , YU Hai tao b , ZHANG Zhi qian a , MIN Xin min c LU GUO ming b and CHI Yu juan b (Department of Applied Chemistry, Harbin institute of technology a, Harbin 150001, P.R. China;College of Ch 出　　处：《Chemical Research in Chinese Universities》索引1999年第15卷第4期,共7页 摘　　要：Quantum chemistry calculations of La , Ca modified and pure PbTiO\-3 nanocrystals were carried out by means of the cluster model in DFT DVM calculating program on which the regularity of the charge distribution was drawn. The analysis of the density of state(DOS) showed that when the cubic phase PbTiO 3 nanocrystal is changed into tetragonal phase, the interaction among Ti 3d , O 2p , and Pb 6p atomic orbitals causes the dipole moment and spontaneous polarization on the axis of the crystal, which resulted in the appearance of ferroelectric phase. At the same time, the dipole moment and the intensity of the spontaneous polarization were calculated as well. 关 键 词：Nanocrystal Density Function Theory LA MODIFIED PbTiO 3 CA MODIFIED PbTiO 3 SPONTANEOUS polarization