三斜水钠锰矿层间阳离子交换作用的拉曼谱学
Raman Spectroscopy of Ion Exchange in Interlayer of Triclinic Birnessite

水钠锰矿为自然界中常见的锰氧化物矿物，其离子交换作用及结构转变理解尚不深刻，矿物表征手段较为局限.为探究水钠锰矿的离子交换特性以及结构转变在拉曼光谱上的反映，利用MnSO4和NaOH合成了三斜晶系的Na型水钠锰矿，进行了NH4+、K+、Mg2+、Ca2+、Ba2+、Co2+、Zn2+的离子交换实验，使用ICPOES、XRD、拉曼光谱等手段对离子交换水钠锰矿进行表征.拉曼光谱分析表明，570～585cm-1与640～655cm-1 两个锰氧八面体伸缩振动模式的相对强度及570～585cm-1 附近拉曼峰峰位指示水钠锰矿的结构对称型；570～585cm-1 拉曼峰强度大、振动频率高指示三斜对称型.280cm-1 与500cm-1 附近的拉曼峰是层间离子种类的识别标志.水钠锰矿层间若为Na+、K+、Mg2+、Ca2+、Ba2+等碱金属、碱土金属离子，则在280cm-1附近存在1个峰值，500cm-1存在2个分立的峰值；其他种类的层间离子仅500cm-1处有1个孤峰，指示层间离子排列无序.
Birnessite is a group of manganese oxide mineral, widely found in nature; however. Its ion exchange behavior and structural transformation have not been fully understood, and the characterization techniques are limited. To study the ion exchange behavior of birnessite and the reflection of structural transformation in Raman spectroscopy, triclinic Nabirnessite using MnSO4 and NaOH was synthesized, and carried out ion exchange experiments on NH4+,K+,Mg2+,Ca2+,Ba2+,Co2+and Zn2+were. Ion exchange birnessite samples were characterized using ICPOES, XRD, and Raman spectroscopy. Raman study shows the relative strength of two stretching vibration modes in ［MnO6］ octahedra around 570-585cm-1 and 640-655cm-1 and the band location of the mode around 570-585cm-1 are indicators of the symmetry of birnessite. High strength and frequency of the mode around 570-585cm-1 are signs of triclinic symmetry. Raman bands around 280cm-1 and 500cm-1 are indicators of interlayer cations. If alkalis and alkalineearth metals (i.e., Na+,K+,Mg2+,Ca2+,Ba2+etc.) are in the interlayer of birnessite, a band around 280cm-1and two separate bands around 500cm-1will appear; whereas other interlayer cations only give rise to one single band at 500cm-1, indicating disorder in the interlayer