采用水热法以TiCl3和Co(CH3COO)2·4H2O为主要原料制备出CoTiO3微晶.利用X射线衍射、透射电子显微镜对产物进行表征,重点研究了晶体的生长规律及结晶动力学.结果表明水热条件下CoTiO3晶体的生长过程是:水热温度为220℃时,晶核首先析出并沿平面铺展;随着反应时间的延长或水热温度的升高,晶核逐渐长大形成类似六边形的片状晶粒；280℃时晶粒开始沿垂直于片层的方向逐层堆积生长,最终形成菱面体晶粒.结晶动力学研究显示:水热条件下,CoTiO3晶体成核速率及生长速率均随温度升高而增长,其成核活化能和表观生长活化能分别为89.18 kJ· mol-1和50.56kJ·mol-1.%CoTiO3 microcrystals were prepared by hydrothermal method using TiCl3 and Co(CH3COO)2 as raw reactants. The crystal growth mechanism and crystallization kinetics of CoTiO3 under hydrothermal circumstances were detailed investigated via XRD and TEM. The results showed that CoTiO3 nuclei precipited from the precursor at 220℃, and firstly grew up into hexagonal flake grain with temperature and reaction hours increased. Later, the hexagonal flakes began to staking one by one along the c axis, forming ilmenite-type rhombohedron grain at 280℃. Crystallization kinetics research revealed that, both the nucleation rate and growth rate of CoTiO3 grain increased with increase of the hydrothermal temperature. The activation energies of CoTiO3 nucleation and crystal growth are 89.18 kJ·mol-1 and 50.56 kJ·mol-1, respectively.
展开▼
