【作者】 刘佳；

【导师】 黄菲；

【作者基本信息】 东北大学 ， 矿产普查与勘探， 2014， 硕士

【摘要】 Fe-S系列矿物是重要的金属硫化物,在多金属矿床中大量存在。矿物的结构在反映晶体性质的同时,也能够反映矿床的成矿过程及矿体存在的物理、化学条件的变化信息。Fe-S系列矿物包括黄铁矿相(FeS2)、白铁矿相(FeS2)、硫复铁矿相(Fe3S4)、磁黄铁矿相(Fe1-xS, x=0～0.223)、陨硫铁(FeS)等。其中黄铁矿为立方晶系,常见形貌为立方体、五角十二面体、八面体及其聚形：磁黄铁矿常见六方、单斜结构,可见少量斜方晶系,并具有复杂的超结构。为确定不同条件中Fe-S矿物的结构特征,综合运用多晶X射线衍射仪(XRD)、透射电子显微镜(TEM)、电子背散射衍射技术(EBSD).激光拉曼光谱仪等现代测试手段对天然和人工合成Fe-S系列矿物的形貌、成分、结构特征做较系统的分析,利用紫外可见光分光光度计对样品进行光伏性能的探索,分析结构对性能的影响。利用TEM测定立方体黄铁矿的衍射谱,建立了[001],[013],[012],[111],[323],[212],[313],[101],[232],[112],[123]等11个晶带的衍射谱图；测定白铁矿的衍射谱,建立了[104],[301],[313],[201],[311],[114],[201],[101]等晶带的衍射谱图。确定水热法合成板片状六方磁黄铁矿[0001],[1 213],[1453],[022 1],[2423],[1011]晶带；单斜磁黄铁矿[110],[010]晶带；运用EBSD测定山西耿庄天然黄铁矿晶须生长方向为<001>,晶须的生长符合定向聚集生长模式；黑龙江老柞山金矿中黄铁矿具有块状、立方体、网格状等形貌,测定其拉曼谱峰为345.43-354.93cm-1,383.43-389.76cm-1；武山铜矿指纹状黄铁矿S/Fe原子不同比值,微量元素的含量也有所变化,反映所受热液变质改造的程度不同,指纹状黄铁矿是低温还原性成矿流体成矿后经泄水作用形成的；湿热条件下合成立方体聚形黄铁矿晶胞参数为：a=b=c=5.417A, α=β=γ=90°;确定水热条件下合成片状黄铁矿[013],[102],[021],[011]晶带；老柞山条带状白铁矿S/Fe>2,为铁亏损型,拉曼谱峰峰位332.76-336.13cm-1,370.76-399.26cm-1,黄铁矿由于环境酸度的变化通过同质多象变体向白铁矿转变不彻底,经重结晶作用后呈立方体存在于白铁矿中；老柞山环带结构为斜方晶系白铁矿,环带拉曼谱峰位378～382cm-1,324～328cm-1。由于成矿热液成分的复杂性和活动的多期性导致不同环带的形成；黑龙江老柞山金矿矿石标本中可见六方磁黄铁矿及单斜磁黄铁矿；水热条件下螺旋生长的磁黄铁矿实现了自然条件下罕见的斜方磁黄铁矿,其生长遵循螺旋生长理论；在较低的温度条件下,合成了纯净的六方板状磁黄铁矿；对不同条件下的Fe-S矿物标准电子衍射谱进行对比,分析不同结构的内在差异,确定矿物变化；将不同条件下的Fe-S系列矿物结构参数进行对比,反演其形成环境变化及有序度；结合本文与前人研究,确定Fe-S系列矿物之间的相互转化；水热法合成粒状黄铁矿样品中含一定量斜方磁黄铁矿,禁带宽度E。为0.6578eV；结构与性能影响机制的初步研究认为FeS2-Fe1-xS结构的光电转化效率较天然黄铁矿光电转化效率高。综上可见,Fe-S系列矿物结构特征及变化规律研究,在纳-微米Fe-S系列矿物结构鉴定、生长条件讨论、晶体结构与性能相关性研究中均具有重要意义。更多还原

【Abstract】 Fe-S series minerals are important metal sulfide minerals which abound in polymetallic deposits. The different structures reflect the nature of the crystal and provide a scientific basis for further study of the physical and chemical environment of crystal growth. Fe-S series minerals include pyrite (FeS2), marcasite (FeS2), greigite phase (Fe3S4), pyrrhotite phase (Fe1-xS, x= 0 to 0.223), troilite (FeS) and so on. Pyrite is cubic with the common morphology of cube, pentagonal dodecahedron, octahedron and their shaped poly. Commonly, the pyrrhotite structures are hexagonal; monoclinic; a small amount of orthorhombic and complex super-structures.To determine the structural characteristics of the Fe-S series minerals from different conditions, we integratly use the XRD; TEM; EBSD; Raman and other modern means to analyse the morphology; composition, structural characteristics of natural and synthetic Fe-S series minerals. Then we explore the photovoltaic performance of the samples by using UV-Vis spectrophotometer, analysis the impact of structure on performance.Using modern test technologies, this thesis systematically observe the morphology and composition characteristics of Fe-S series minerals. Then, we utilize the XRD; TEM; EBSD; Raman to determine the structure of the sample; take a comparatively analysis of the structure parameters; use UV-visible-near infrared spectrophotometer to determine the light absorption characteristics of the sample.Through the TEM, we determine the [001], [013], [012], [111], [323], [212], [313], [101], [232], [112], [123] zone of pyrite; the [104], [301], [313], [201], [311], [114], [201], [101] zone of marcasite; the [0001], [1213], [1453], [021], [2423], [1011] zone of hexagonal pyrrhotite and the [110], [010] zone of monoclinic pyrrhotite systhized under hydrothermal conditions.The crystal orientation of pyrite whiskers from Shanxi Gengzhuang is<001>, the growth of the whiskers meet the directional aggregation; The pyrite from the gold mine, Heilongjiang Laozuoshan are cube and grid-like, the Raman spectra are measured as 345.43～354.93cm-1 383.43～389.76cm-1; The different ratios of Fe/S and content of trace elements in laminated pyrite from Wushan copper mine reflect a different degree of hydrothermal metamorphism, the pyrite is formed by the water release of the reductive mineralization fluid; The cell parameters of cube poly-shaped pyrite synthesized under hot and humid conditions are:a= b= c=5.417A, α=β=γ=90°; Through the TEM, we determine the [013], [102], [021], [Oil] zone of sheet pyrite synthesized by hydrothermal;The S/Fe ratio of banded marcasite is larger than 2, the Raman peak positions are 332.76 ～336.13cm-1,370.76～399.26cm-1, the appearance of cube pyrite in banded marcasite is due to the uncompletely conversion from pyrite to marcasite by the changing of environment; The Raman spectra of ring banded is 378-382cm-1,324-328cm-1. The complexity of hydrothermal fluid results in the formation of different morphology.The visible pyrrhotite in Heilongjiang Laozuoshan is hexagonal and monoclinic; we achieve the rare orthorhombic pyrrhotite with spiral growth under hydrothermal conditions, and get the pure hexagonal plate-pyrrhotite at lower temperature.Compare the standard electron diffraction of Fe-S series minerals under different conditions to speculate the arrangement of initial lattice points; Take a classified comparison of the structural parameters of different Fe-S series minerals to inverse the the changement of formation environmental and crystallization degree; Combine with previous studies, we ascertain the conversion of Fe-S series.The samples are cubic pyrite with a certain amount of pyrrhotite (Fe1-xS) synthesized by hydrothermal method. The band gap value is 0.6578eV. The limiting conversion efficiency we achieved is about 15%. The internal structure of mineral is an important factor effecting the photoelectric conversion. The heterostructures of FeS2-Fe1-xS synthesized under hydrothermal conditions can improve the photoelectric conversion efficiency.In summary, the study of structure and variation of nano-micron Fe-S series minerals is of great significance on structure identification; discussion of growing conditions; correlation between crystal structure and properties.更多还原