水热法合成FeS_2粉晶及其生长热动力学的研究  

Hydrothermal synthesis of iron pyrite (FeS_2 ) crystalpowder and thermal-kinetic study on crystal growth

作　　者：段鹤[1] 郑毓峰[1] 张校刚[2] 孙言飞[1] 董有忠[1] 

机构地区：[1]新疆大学物理系,乌鲁木齐830046 [2]新疆大学化学化工学院,乌鲁木齐830046

出　　处：《物理学报》2005年第4期1659-1664,共6页Acta Physica Sinica

基　　金：国家自然科学基金 (批准号 :5 0 0 62 0 0 2 )资助的课题~~

摘　　要：采用溶胶_凝胶水热法合成了单相黄铁矿结构的FeS2 粉晶 .用x射线衍射、傅氏变换红外光谱等分析手段对FeS2 粉晶进行了表征 ,以简化的数学模型及相变理论讨论了晶体生长过程 .结果表明 :FeS2 晶粒的生长过程属于相变与扩散的混合机制 ,符合经时间指数修正的二次方动力学方程 ,是一个生长速率随时间变化的过程 ;水热晶化温度高于 4 5 3K、反应时间超过 18h且有适量的硫参与反应时 ,可得到单相的黄铁矿型的FeS2 .该过程可分为三个阶段 :前期为白铁矿和黄铁矿的成核孕育阶段 ,中期为FeS2 晶核以黄铁矿吞并白铁矿的相变方式逐渐长大的阶段 ,后期为小晶粒融合而大晶粒继续长大的扩散生长过程 .Single-phase iron pyrite (FeS2) crystalpowder was prepared by sol-gel hydrothermal method, which was characterized via x-ray diffraction, Fourier transform infrared and scanning electron microscope. A simplified mathematic model was established to analyze the crystal growth process. Results indicate that phase transformation and diffusion mechanism control the process, which fits the second-order kinetic equation with an exponent 3.215 for time t. This is a decelerated process that can be divided into three steps: during the first period, marcasite and pyrite phases are produced, and then with inducting of sulfur into the reaction, the process is dominated by the merging of marcasite into pyrite. Ultimately, with the fuse of small grains and the growing of larger ones, single-phase iron pyrite crystals grow up through diffusion mechanism.

关 键 词：溶胶一凝胶水热法 FeS2粉晶 晶粒生长 热动力学 

分 类 号：O781[理学—晶体学]