拉曼光谱研究天然FeS_2晶须结构及其相变规律

Study on Structure and Phase Transformation Laws of Natural FeS_2 Whisker by Raman Spectroscopy

利用显微激光拉曼技术研究了山西耿庄天然纳-微米FeS2晶须的结构。发现FeS2晶须中有白铁矿和黄铁矿两种结构类型。较粗的藕节状、粗柱状、串珠状等不规则形貌为白铁矿相,直线状、平直、表面光滑的晶须为黄铁矿相。耿庄FeS2晶须结晶生长早期以白铁矿相为主,中期是白铁矿和黄铁矿型结构共存,晚期以黄铁矿相为主。晶须生长过程有早期白铁矿结晶向晚期黄铁矿结晶转变的趋势。而且有黄铁矿包覆白铁矿的生长现象。FeS2晶须结构相变规律与形貌、形成时间和成分特点具有关联性。

FeS2 belongs to sulfide, including pyrite of isometric system and marcasite of orthorhomhic system. The FeS2 discovered in Gengzhuang, Shanxi Province, was growing in the form of whisker. The study with scanning electron microscopy and electron probe show that the mineral components of FeS2 vary regularly. The structure of natural nano-mieron FeS2 whisker was determined by micro-Raman spectroscopy. The results show that there exist two types of structure in FeS2 whiskers： pyrite and marcasite. Marcasite presents irregular shapes, such as coarse lotus root joints, crude columnar or beaded. Pyrite exists in the shape of straight line and smooth surface. In the early growing stage, Gengzhuang FeS2 whisker was mainly marcasite-type structure; in the middle stage it was coexistent structure of pyrite-and marcasite-type; in the late stage it was mainly pyritetype. The growing stages of the whisker FeS2 show the phase transformation laws. Moreover, during the growing process marcasite was growing with pyrite coated on. Study on FeS2 whisker structure shows that there are correlations between phase transformation laws of the structure and forms, and between the forming time and the composition characteristics.