共查询到18条相似文献，搜索用时 125 毫秒
1.
广西阳朔长期出产宝石级磷氯铅矿,迄今未见其矿物学和振动光谱的研究报道。采用能量色散X射线荧光光谱、X射线粉末晶体衍射、红外光谱和拉曼光谱分析了14颗阳朔磷氯铅矿。该矿物为半透明的黄绿色六方柱,相对密度为6.484～7.310,白色条痕,硬度为4,化学成分以铅、磷和氯为主。红外光谱在1 060～920 cm-1和580～540 cm-1区域观察到属于PO43-的伸缩和弯曲振动带,平行和垂直光轴的谱带差异明显;部分样品观察到AsO43-振动弱带,说明结构中有少量PO43-被替代。拉曼光谱观察到916/940 cm-1属于PO43-伸缩振动强带、位于390/414/542/572 cm-1系列弯曲振动带和160～262 cm-1晶格振动带。这些谱带随着测试方向不同而变化,反映出结构中的PO4 相似文献
2.
异极矿热相变过程的高温原位拉曼光谱 总被引：1，自引：0，他引：1
利用高温拉曼光谱技术,对异极矿进行了原位拉曼光谱的测试和研究。结果表明,异极矿加热至800 K时,与结晶水(H2O)中O-H伸缩振动对应的3 470 cm-1特征拉曼谱峰消失,但标志硅酸盐骨架[Si2O7] (Q1)结构的特征谱峰926 cm-1未受影响,表明结晶水的丢失并不影响异极矿的整体结构。当加热至1 050 K,反映结构水O-H伸缩振动的特征峰3 580 cm-1消失,与Q1结构单元Si-Onb对称伸缩振动相对应的特征峰926 cm-1强度逐渐减小,并出现与Q0相对应的852.4 cm-1特征峰。这表明加热到1 050 K时,异极矿开始出现相变。当升温达1 100 K以上,结构水(OH)的特征谱峰(3 580 cm-1)消失,与Si-Onb对称伸缩振动对应的特征拉曼谱峰变为855 cm-1,这标志着异极矿原有的Q1结构已完全转变为硅锌矿的Q0结构 ([SiO4]结构),也就是说异极矿已完成向硅锌矿的转变。 相似文献
3.
利用拉曼光谱和红外光谱研究了方解石、白云石和菱镁矿的光谱学特征,探究了影响三种矿物红外辐射性能的因素。三种矿物的拉曼光谱(Raman)、中红外吸收光谱(MIR)、远红外吸收光谱(FIR)显示随着矿物中镁含量的增大将会影响CO32-的面外弯曲振动(ν2)、反对称伸缩振动(ν3)和平面内弯曲振动(ν4),使各光谱特征峰均向高频端迁移。基于黑体辐射定律以及在80 ℃、400~2 000 cm-1矿物的辐射能量谱,结果显示方解石、白云石、菱镁矿的发射率依次减少(0.951,0.938,0.895)。三种矿物的红外吸收光谱和发射光谱中的振动位置均受CO32-基频的显著影响,在1 300~1 650 cm-1均产生宽的低吸收带,该吸收带与CO32-的反对称伸缩振动相关,且吸收带范围(202,236,272 cm-1)与发射率之间呈负相关关系。因此,当最强化学键的振动出现在发射光谱窄的吸收带范围内会产生相对较高的辐射能和发射率。此外,矿物的晶体结构也会影响发射率,大的离子半径、键长和晶胞体积将降低辐射过程中能量的吸收,增强辐射特性。综上研究结果,方解石、白云石和菱镁矿的拉曼光谱和红外光谱揭示了金属原子的相对质量对光谱学特征的显著影响,其发射率可能受到C—O键的反伸缩振动范围、最强吸收带控制的最低发射率以及矿物晶体结构的共同影响。这项研究呈现了必要的光谱信息和热发射率数据以识别特定的碳酸盐矿物,为类似矿物的光谱特征研究奠定了基础;同时为进一步认识地壳中大量的碳酸盐矿物提供了研究方法,也为地外勘探的深入研究给予相关的理论基础。 相似文献
4.
天然气水合物的晶体结构主要取决于客体分子种类与组成,目前单组分水合物的结构和谱学特征较为明确,但多组分水合物相关研究较少。为解决多组分水合物的结构识别问题,探讨其谱学特征,本文实验合成了甲烷-丙烷(CH4-C3H8)和甲烷-四氢呋喃(CH4-THF)两种含CH4双组分水合物以及CH4、C3H8和THF等三种单组分水合物,并采用低温X射线粉晶衍射(PXRD)和显微激光拉曼光谱进行了表征。结果表明:CH4-C3H8和CH4-THF双组分水合物的晶格常数a分别为17.2312×10-10 m和17.2241×10-10 m,为典型的Ⅱ型结构水合物,与相应C3H8和THF单组分水合物结构相同。在CH4-C3H8水合物中,CH4在大、小笼中均有分布,呈现两个特征拉曼峰(2900cm-1和2911cm-1);C3H8仅分布在大笼,与单组分水合物相比,其C—H伸缩振动峰峰位几无变化,而C—C伸缩振动峰(873cm-1)向低频迁移约3cm-1。在CH4-THF水合物中,大笼被THF占据,CH4仅填充在小笼中(2910cm-1);双组分水合物中,THF分子C—C和C—H伸缩振动峰峰位均与单组分水合物基本一致。分析认为,含CH4双组分水合物的结构类型与其相应的大分子水合物一致,大分子对双组分水合物的晶体结构特征具有决定作用。同时,大分子影响了CH4分子在笼型结构中的分布,致使双组分水合物的拉曼光谱特征存在显著差异。研究结论对基于谱学特征识别多组分水合物微观结构具有重要的指导意义。 相似文献
5.
天然气和液态混合烷烃在不同压力和温度下的原位拉曼测试表明,天然气和液态混合烷烃的拉曼特征峰随温度增高向高波数移动,随压力增大而表现出不同的拉曼位移趋势。2917 cm-1左右为天然气的C–H对称伸缩振动峰(ν1),随压力增大向低波数移动,甲烷占烃类的比例和C2+烃类含量对ν1拉曼位移有影响。<150℃时,液态混合烷烃的C–H对称伸缩振动峰和C–H不对称伸缩振动峰随压力增加向高波数移动,拉曼特征峰位移与压力相关性曲线变化趋势一致;≥150℃时,液态混合烷烃的部分拉曼特征峰随压力增大向低波数移动,拉曼特征峰位移与压力相关性曲线变化趋势不一致。 相似文献
6.
This work aims to quantify sulfate ion concentrations in the system Na2SO4-H2O using Raman micro-spectroscopy.Raman spectra of sodium sulfate solutions with known concentrations were collected at ambient temperature（293 K） and in the 500 cm1-4000 cm-1 spectral region.The results indicate that the intensity of the SO42- band increases with increasing concentrations of sulfate ion.A linear correlation was found between the concentration of SO42-（c） and parameter I1,which represents the ratio of the area of the SO42- band to that of the O-H stretching band of water（As/Aw）:I1=-0.00102+0.01538 c.Furthermore,we deconvoluted the O-H stretching band of water(2800 cm-1-3800 cm-1) at 3232 and 3430 cm-1 into two sub-Gaussian bands,and then defined Raman intensity of the two sub-bands as ABi(3232 cm-1) and AB2(3430 cm-1),defined the full width of half maximum（FWHM） of the two sub-bands as WB1(3232 cm-1) and WB2(3430 cm-1).A linear correlation between the concentration of SO42-（c） and parameter I2,which represents the ratio of Raman intensity of SO42-（As）(in 981 cm-1) to(AB1+AB2),was also established:I2=-0.0111+0.3653 c.However,no correlations were found between concentration of SO42-（c） and FWHM ratios,which includes the ratio of FWHM of SO42-（Ws） to WB1 WB2 and WB1+B2(the sum of WB1 and WB2),suggesting that FWHM is not suitable for quantitative studies of sulfate solutions with Raman spectroscopy.A comparison of Raman spectroscopic studies of mixed Na2SO4 and NaCI solutions with a constant SO42- concentration and variable CI- concentrations suggest that the I\ parameter is affected by CI-,whereas the I2 parameter was not.Therefore,even if the solution is not purely Na2SO4-H2O,SO42- concentrations can still be calculated from the Raman spectra if the H2O band is deconvoluted into two sub-bands,making this method potentially applicable to analysis of natural fluid inclusions. 相似文献
7.
目前缅甸抹谷矿区开采的蓝宝石原石约80%都要经过优化处理才能投入市场,其中主要为热处理。本文对缅甸抹谷Baw-mar矿区蓝宝石进行不同温度制度的热处理,并利用电子探针、X射线粉晶衍射仪(XRD)、紫外-可见-近红外光谱仪、傅里叶红外光谱仪和激光拉曼光谱仪对其热处理前后的谱学特征进行了对比研究。结果表明,1 300℃热处理后所有样品2θ<60°的XRD衍射峰开始向低角度方向偏移,晶胞参数c/a值随热处理温度升高而降低,推测与其晶体结构在高温下发生畸变有关;Baw-mar矿区蓝宝石的主要致色元素是Fe、Ti和V,其中Fe和Ti共同导致其呈蓝色,V使其略带绿色调,部分样品的灰色调主要由Ni所致;热处理后样品中Fe2+-Ti4+荷移增强,Fe2+-Fe3+荷移减弱,导致585 nm紫外吸收带增强,746和764 nm吸收峰减弱,同时样品颜色变蓝且灰色调减弱;红外光谱中,样品出现1 988、2 123 cm-1硬水铝石羟基倍频振动吸收峰和3 619、3 696 cm-1<... 相似文献
8.
实验研究了4A沸石分子筛经熔融盐处理后对KNO3和NH4NO3的吸持作用。结果表明：在实验条件下,KNO3处理后的4A沸石中含钾(以K2O计)15.01%,含NO-3 9.23%;NH4NO3处理后的4A沸石中含NO-3 10.78%,含NH+4 0.94%。熔融盐处理后的样品X射线衍射峰相对强度发生了变化,红外光谱中1 640 cm-1附近水的吸收带强度减弱,1 390 cm-1附近出现的NO-3离子的强吸收带及825 cm-1附近出现的NO-3离子的弱吸收带,以及热重-差热曲线中KNO3和NH4NO3的热失重和分解热效应均证明沸石中吸持盐的存在。处理后4A沸石分子筛的基本骨架结构没有被破坏,吸持盐的4A沸石对营养盐的储备大大提高,是潜在的缓释肥料。 相似文献
9.
采用显微镜和XRD,EMPA,FTIR,RAMAN,TGA等现代测试方法对内蒙赤峰鱼眼石的晶体形态、矿物组合、化学成分、谱学特征、热力学性质等进行了测试分析,初步探讨了鱼眼石晶体形态的成因以及水的赋存状态。赤峰鱼眼石晶体呈粒状—假立方状,由四方柱{100}、四方双锥{111}和平行双面{001}聚合而成,无色-浅粉红色,玻璃光泽,透明到半透明,与钙铁辉石、雪硅钙石和毒砂等矿物共生。赤峰鱼眼石的主要化学成分为w(SiO_2)50.22%~52.73%,w(CaO)24.16%~25.28%,w(K_2O)3.57%~5.80%和w(F)2.62%~3.48%,含有少量的Na_2O,Al_2O_3和Cr_2O_3,平均成分的晶体化学式为:(K0.964Na0.109)1.073Ca4.036[(Si7.727Al0.091Cr0.073)7.891O20](F0.828OH0.172)1.000·7.775H_2O。硅的含量不足导致硅氧四面体层活性氧与层间阳离子的键强增大,促使鱼眼石晶体沿c轴方向的生长,形成粒状—假立方状晶体形态。红外光谱中3 556 cm-1和1 691 cm-1吸收峰以及96.7℃,255.9℃,418.9℃,437.7℃的主要失水温度均表明赤峰鱼眼石中的水属于结晶水,而600℃以后仍有少量的失重,以及红外光谱中3 418 cm-1和3 242 cm-1吸收峰的出现,又反映出赤峰鱼眼石中部分水具有结构水的特点。 相似文献
10.
青藏高原北部白榴碧玄岩年代学及地球化学研究 总被引：1，自引：0，他引：1
本文在可可西里北部边缘银顶山地区首次发现含橄榄石的高镁高钾质超基性火山岩。火山岩在阿尼玛卿-昆仑-木孜塔格缝合带南侧呈熔岩残丘形式产出,分布面积约为0.2 km2,其形成时代为上新世(5～4 Ma),是岩浆的快速侵位-喷溢的结果。斑晶主要为橄榄石(10%～12%)+白榴石(21%～27%)+霞石(13%～16%)±透辉石(29%～31%),基质主要为透辉石+云母+Fe-Ti氧化物+玻璃,定名为白榴碧玄岩。对3个样品51个点的橄榄石电子探针数据计算显示,橄榄石牌号为Fo74-87Fa13-26,属贵橄榄石,岩石中的橄榄石均不存在扭折带,表明这些橄榄石很可能是岩浆结晶的产物,而非岩浆捕获体。通过计算,银顶山地区橄榄石的结晶温度大约在1 226 ℃～1 234 ℃左右。白榴碧玄岩的化学组分:SiO2<45%,MgO>10%, Na2O+K2O>8%,Mg#(68.84～70.80),而Cr(149×10-6～156×10-6)和Ni(138×10-6～151×10-6),87Sr/86Sr(约0.708 6)和143Nd/144 Nd(约0.512 4),处于EMII源区范围内。初步认为藏北地区上新世超基性火山岩来自于较深的源区,最有可能是软流圈顶部地幔的局部熔融,并受到俯冲地壳物质的交代。 相似文献
11.
本文百次研究了山东金伯利岩中橄榄石的产状、含量、大小、世代、形态、颜色、环带、矿物包体、折光率、2V、化学成分、端员组分特征及红外光谱和穆斯堡尔谱特征,并分析研究了橄榄石的成因。指出了无色—浅绿色的、含MgO、Cr2O3、NiO高的橄榄石是找金刚石矿的指示性矿物。 相似文献
12.
Xiaozhi Yang Leonid Dubrovinsky M. A. G. M. Manthilake Qingguo Wei 《Physics and Chemistry of Minerals》2012,39(1):57-64
In situ Raman spectra of hydrous wadsleyite (β-Mg2SiO4) with ~1.5 wt% H2O, synthesized at 18 GPa and 1,400°C, have been measured in an externally heated diamond anvil cell up to 15.5 GPa and 673 K.
With increasing pressure (at room temperature), the three most intense bands at ~549, 720 and 917 cm−1 shift continuously to higher frequencies, while with increasing temperature at 14.5 GPa, these bands generally shift to lower
frequencies. The temperature-induced frequency shifts at 14.5 GPa are significantly different from those at ambient pressure.
Moreover, two new bands at ~714 and ~550 cm−1 become progressively significant above 333 and 553 K, respectively, and disappear upon cooling to room temperature. No corresponding
Raman modes of these two new bands were reported for wadsleyite at ambient conditions, and they are thus probably related
to thermally activated processes (vibration modes) at high-pressure and temperature conditions. 相似文献
13.
Bruno Reynard Pierre-Emmanuel Petit François Guyot Philippe Gillet 《Physics and Chemistry of Minerals》1994,20(8):556-562
Raman spectra of Mg2GeO4-olivine were obtained from ambient pressure up to 34 GPa at ambient temperature. Under quasi-hydrostatic pressure conditions, the following modifications in the Raman spectra occur as pressure increases: 1) near 11 GPa, two sharp extra bands appear in the 600–700 cm?1 frequency range, and increase in intensity with respect to the olivine bands; 2) above 22 GPa, these two bands become very intense, and the number, position and relative intensity of the other vibrational bands drastically change; 3) the intensity of sharp bands progressively decreases above 25 GPa. The transformation occurs at lower pressures under non-hydrostatic conditions. During decompression to atmospheric pressure, the high-pressure phase partially reverts to olivine. These observations can be interpreted as the progressive metastable transformation from the olivine structure to a crystalline phase with four-fold coordinated Ge, in which the GeO4 tetrahedra are polymerized. We propose that the metastable high-pressure phase is a structurally disordered spinelloid close to the hypothethical ω- or ?*-phase, and forms by a shear mechanism assisted by the development of a dynamical instability in the olivine structure. Implications for the transformations undergone by olivines under far-from-equilibrium conditions (e.g. in subducting lithospheric slabs and in shocks) are discussed. 相似文献
14.
采用x射线粉晶衍射（XRD）、博里叶变换红外光谱（FTI码以及拉曼光谱等方法对安徽马鞍山具磷灰石假象的绿松石进行了研究。结果表明：其主要矿物组成为绿松石,保留了磷灰石六边形的形态特征。XRD~U试的特征谱线d值为36745～36748（111）、29008～29025（123）、34247～34293（2101、32709～32781（113）、61626～61781（011）3020130～20162（301）,与绿松石的标准衍射谱线基本致。红外光谱测试分析表明：3510～3465cm。间的谱带归属绿松石0（OH）的伸缩振动,3300～3070cm’间的谱带归属为绿松Nu（M-H。O）伸缩振动,1210-1012cm’间的谱带归属为绿松石U3口O。）ira缩振动,在838cm。附近的吸收谱带归属为绿松石6（OH）弯曲振动,655-480cm。间的谱带归属为绿松石u4（P04）弯曲振动。拉曼光谱测试分析表明：3466cm’附近的尖锐拉曼谱峰归属于绿松石（OH）基团的伸缩振动所致,宽缓的拉曼谱峰3281cm’~03078cm’归属于绿松石中水合络离子的伸缩振动,798cm’谱峰则是由于OH的弯曲振动所致。 相似文献
15.
Shuangmeng Zhai Weihong Xue Chung-Cherng Lin Xiang Wu Eiji Ito 《Physics and Chemistry of Minerals》2011,38(8):639-646
High-temperature Raman spectra and thermal expansion of tuite, γ-Ca3(PO4)2, have been investigated. The effect of temperature on the Raman spectra of synthetic tuite was studied in the range from 80 to 973 K at atmospheric pressure. The Raman frequencies of all observed bands for tuite continuously decrease with increasing temperature. The quantitative analysis of temperature dependence of Raman bands indicates that the changes in Raman frequencies for stretching modes (ν3 and ν1) are faster than those for bending modes (ν4 and ν2) of PO4 in the present temperature range, which may be attributed to the structural evolution of PO4 tetrahedron in tuite at high temperature. The thermal expansion of tuite was examined by means of in situ X-ray diffraction measurements in the temperature range from 298 to 923 K. Unit cell parameters and volume were analyzed, and the thermal expansion coefficients were obtained as 3.67 (3), 1.18 (1), and 1.32 (3) × 10?5 K?1 for V, a, and c, respectively. Thermal expansion of tuite shows an axial anisotropy with a larger expansion coefficient along the c-axis. The isothermal and isobaric mode Grüneisen parameters and intrinsic anharmonicity of tuite have been calculated by using present high-temperature Raman spectra and thermal expansion coefficient combined with previous results of the isothermal bulk modulus and high-pressure Raman spectra. 相似文献
16.
High pressure and temperature reactions of a mixture of forsterite and hydrogen molecules have been carried out using a laser
heated diamond anvil cell at 9.8–13.2 GPa and ~1,000 K. In situ X-ray diffraction measurements showed no sign of decomposition
or phase transitions of the forsterite under these experimental conditions, indicating that the olivine structure was maintained
throughout all runs. However, a substantial expansion of the unit cell volume of the forsterite was observed for samples down
to ~3 GPa upon quenching to ambient pressure at room temperature. The Raman spectroscopy measurements under pressure showed
significant shifts of the Raman peaks of the Si–O vibration modes for forsterite and of the intramolecular vibration mode
for H2 molecules toward a lower frequency after heating. Additionally, no OH vibration modes were observed by Raman and FT-IR spectroscopic
measurements. These lines of evidence show that the observed volume expansion in forsterite is not explained by the incorporation
of hydrogen atoms as hydroxyl, but suggest the presence of hydrogen as molecules in the forsterite structure under these high
pressure and temperature conditions. 相似文献
17.
The temperature dependence (at ambient pressure) of the Raman spectra of both the quartz- and rutile-types of GeO2 has been studied from 109 to 874?K. All spectra were corrected for the effects of temperature and are presented in their reduced form to allow a direct comparison of intensities at all temperatures. In the quartz-type GeO2, the Raman bands above 400?cm?1 exhibited relatively larger temperature dependences and at least four of the bands in this region vary nonlinearly with increasing temperature. Deconvolution of the most intense Raman band at 700?cm?1 in the rutile-type GeO2 revealed the presence of a previously unreported band at 684?cm?1 at 298?K which may arise from splitting of the A1g mode. A nonlinear temperature dependence was observed for all the Raman bands above 600?cm?1 in the rutile-type GeO2 with the new band at 684?cm?1 exhibiting the largest curvature. In common with previous studies of rutile-type oxides, the B1g mode at 171?cm?1 showed anomalous behaviour by increasing linearly in frequency with increasing temperature. In a separate experiment, the oxidation of metallic germanium in air demonstrated that the quartz-type GeO2 is the preferred form of germanium oxide at temperatures above 745?K at atmospheric pressure. Thermodynamic calculations predict that the rutile-form of GeO2 should be the stable species under these conditions. This suggests that atmospheric gases may have a marked effect on the kinetics and stability of the quartz and rutile forms of GeO2. 相似文献
18.
Vibrational properties of diaspore, α-AlOOH, have been re-investigated using room-temperature single-crystal Raman spectroscopy
and low-temperature powder infrared (IR) transmission spectroscopy. First-principles harmonic calculations based on density
functional theory provide a convincing assignment of the major Raman peaks and infrared absorption bands. The large width
of the Raman band related to OH stretching modes is ascribed to mode–mode anharmonic coupling due to medium-strength H-bonding.
Additional broadening in the powder IR spectrum arises from depolarization effects in powder particles. The temperature dependence
of the IR spectrum provides a further insight into the anharmonic properties of diaspore. Based on their frequency and temperature
behavior, narrow absorption features at ~2,000 cm−1 and anti-resonance at ~2,966 cm−1 in the IR spectrum are interpreted as overtones of fundamental bending bands. 相似文献