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1.
    
The mixed anion mineral chalcophyllite Cu18Al2(AsO4)4(SO4)3(OH)24·36H2O has been studied by using Raman and infrared spectroscopies. Characteristic bands associated with arsenate, sulfate and hydroxyl units are identified. Broad bands in the OH stretching region are observed and are resolved into component bands. Estimates of hydrogen bond distances were made using a Libowitzky function. Both short and long hydrogen bonds were identified. Two intense bands at 841 and ∼814 cm−1 are assigned to the ν1 (AsO4)3− symmetric stretching and ν3 (AsO4)3− antisymmetric stretching modes. The comparatively sharp band at 980 cm−1 is assigned to the ν1 (SO4)2− symmetric stretching mode, and a broad spectral profile centred upon 1100 cm−1 is attributed to the ν3 (SO4)2− antisymmetric stretching mode. A comparison of the Raman spectra is made with other arsenate‐bearing minerals such as carminite, clinotyrolite, kankite, tilasite and pharmacosiderite. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

2.
    
The mineral dussertite, a hydroxy‐arsenate mineral with formula BaFe3+3(AsO4)2(OH)5, has been studied by Raman spectroscopy complemented with infrared spectroscopy. The spectra of three minerals from different origins were investigated and proved to be quite similar, although some minor differences were observed. In the Raman spectra of the Czech dussertite, four bands are observed in the 800–950 cm−1 region. The bands are assigned as follows: the band at 902 cm−1 is assigned to the (AsO4)3−ν3 antisymmetric stretching mode, the one at 870 cm−1 to the (AsO4)3−ν1 symmetric stretching mode, and those at 859 and 825 cm−1 to the As‐OM2 + /3+ stretching modes and/or hydroxyl bending modes. Raman bands at 372 and 409 cm−1 are attributed to the ν2 (AsO4)3− bending mode and the two bands at 429 and 474 cm−1 are assigned to the ν4 (AsO4)3− bending mode. An intense band at 3446 cm−1 in the infrared spectrum and a complex set of bands centred upon 3453 cm−1 in the Raman spectrum are attributed to the stretching vibrations of the hydrogen‐bonded (OH)− units and/or water units in the mineral structure. The broad infrared band at 3223 cm−1 is assigned to the vibrations of hydrogen‐bonded water molecules. Raman spectroscopy identified Raman bands attributable to (AsO4)3− and (AsO3OH)2− units. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

3.
    
The Raman spectrum of bukovskýite [Fe3+2(OH)(SO4)(AsO4)· 7H2O] has been studied and compared with that of an amorphous gel containing specifically Fe, As and S, which is understood to be an intermediate product in the formation of bukovskýite. The observed bands are assigned to the stretching and bending vibrations of (SO4)2− and (AsO4)3− units, stretching and bending vibrations and vibrational modes of hydrogen‐bonded water molecules, stretching and bending vibrations of hydrogen‐bonded (OH)− ions and Fe3+ (O,OH) units. The approximate range of O H···O hydrogen bond lengths was inferred from the Raman spectra. Raman spectra of crystalline bukovskýite and of the amorphous gel differ in that the bukovskýite spectrum is more complex, the observed bands are sharp and the degenerate bands of (SO4)2− and (AsO4)3− are split and more intense. Lower wavenumbers of δ H2O bending vibrations in the spectrum of the amorphous gel may indicate the presence of weaker hydrogen bonds compared to those in bukovskýite. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

4.
    
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5.
    
Raman spectra of natrouranospinite complemented with infrared spectra were studied and related to the structure of the mineral. Observed bands were assigned to the stretching and bending vibrations of (UO2)2+ and (AsO4)3− units and of water molecules. U O bond lengths in uranyl and O H···O hydrogen bond lengths were calculated from the Raman and infrared spectra. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

6.
    
Raman spectra of metauranospinite Ca[(UO2)(AsO4)]2·8H2O complemented with infrared spectra were studied. Observed bands were assigned to the stretching and bending vibrations of (UO2)2+ and (AsO4)3− units and of water molecules. U O bond lengths in uranyl and O H···O hydrogen bond lengths were calculated from the Raman and infrared spectra. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

7.
    
Raman spectra of two well‐defined types of koritnigite crystals from the Jáchymov ore district, Czech Republic, were recorded and interpreted. No substantial differences were observed between both crystal types. The observed Raman bands were attributed to the (AsO3OH)2− stretching and bending vibrations as well as stretching and bending vibrations of water molecules and hydroxyl ions. The non‐interpreted Raman spectra of koritnigite from the RRUFF database and the published infrared spectra of cobaltkoritnigite were used for comparison. The O H···O hydrogen bond lengths in the crystal structure of koritnigite were inferred from the Raman spectra and compared with those derived from the X‐ray single‐crystal refinement. The presence of (AsO3OH)2− units in the crystal structure of koritnigite was proved from the Raman spectra, which supports the conclusions of the X‐ray structure analysis. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

8.
ABSTRACT

Raman spectra of the uranyl-containing mineral coconinoite, Fe2Al2(UO2)2(PO4)4(SO4)(OH)2 · 20H2O, are presented and compared with the mineral's infrared spectra. Bands connected with (UO2)2+, (PO4)3?, (SO4)2?, (OH)?, and H2O stretching and bending vibrations are assigned. Approximate U?O bond lengths in uranyl, (UO2)2+, and O?H…O hydrogen bond lengths are calculated from the wavenumbers of the U?O stretching vibrations and (OH)? and H2O stretching vibrations, respectively, and compared with published data for similar natural and synthetic compounds.  相似文献   

9.
    
The removal of arsenate anions from aqueous media, sediments and wasted soils is of environmental significance. The reaction of gypsum with the arsenate anion results in pharmacolite mineral formation, together with related minerals. Raman and infrared (IR) spectroscopy have been used to study the mineral pharmacolite Ca(AsO3OH)· 2H2O. The mineral is characterised by an intense Raman band at 865 cm−1 assigned to the ν1 (AsO3)2− symmetric stretching mode. The equivalent IR band is found at 864 cm−1. The low‐intensity Raman bands in the range from 844 to 886 cm−1 provide evidence for ν3 (AsO3) antisymmetric stretching vibrations. A series of overlapping bands in the 300‐450 cm−1 region are attributed to ν2 and ν4 (AsO3) bending modes. Prominent Raman bands at around 3187 cm−1 are assigned to the OH stretching vibrations of hydrogen‐bonded water molecules and the two sharp bands at 3425 and 3526 cm−1 to the OH stretching vibrations of only weakly hydrogen‐bonded hydroxyls in (AsO3OH)2− units. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

10.
    
Raman spectroscopy has been used to study the rare‐earth mineral churchite‐(Y) of formula (Y,REE)(PO4) ·2H2O, where rare‐earth element (REE) is a rare‐earth element. The mineral contains yttrium and, depending on the locality, a range of rare‐earth metals. The Raman spectra of two churchite‐(Y) mineral samples from Jáchymov and Medvědín in the Czech Republic were compared with the Raman spectra of churchite‐(Y) downloaded from the RRUFF data base. The Raman spectra of churchite‐(Y) are characterized by an intense sharp band at 975 cm−1 assigned to the ν1 (PO43−) symmetric stretching mode. A lower intensity band observed at around 1065 cm−1 is attributed to the ν3 (PO43−) antisymmetric stretching mode. The (PO43−) bending modes are observed at 497 cm−1 (ν2) and 563 cm−1 (ν4). Some small differences in the band positions between the four churchite‐(Y) samples from four different localities were found. These differences may be ascribed to the different compositions of the churchite‐(Y) minerals. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

11.
    
Hydrotalcites have been synthesised using solutions of three different pH values to assess the effect of pH on the uptake of arsenate and vanadate. The ability of these hydrotalcites to remove vanadate and arsenate from solution has been determined by inductively coupled optical emission spectroscopy. Raman spectroscopy was used to monitor changes in the anionic species for hydrotalcites synthesised at different pH values. The results show a reduction in the concentration of arsenate and vanadate anions that are removed in extremely alkaline solutions. Hydrotalcites containing arsenate and vanadate are stable in solutions up to pH 10. Exposure of these hydrotalcites to higher pH values results in the removal of large percentages of arsenate and vanadate from the hydrotalcite interlayer. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

12.
    
Raman spectrum of burgessite, Co2(H2O)4[AsO3OH]2· H2O, was studied, interpreted and compared with its infrared spectrum. The stretching and bending vibrations of (AsO3) and As‐OH units, as well as the stretching, bending and libration modes of water molecules and hydroxyl ions were assigned. The range of O H···O hydrogen bond lengths was inferred from the Raman and infrared spectra of burgessite. The presence of (AsO3OH)2− units in the crystal structure of burgessite was proved, which is in agreement with its recently solved crystal structure. Raman and infrared spectra of erythrite inferred from the RRUFF database are used for comparison. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

13.
    
The selected arsenite minerals leiteite, reinerite and cafarsite have been studied by Raman spectroscopy. Density functional theory (DFT) calculations enabled the position of the AsO22− symmetric stretching mode at 839 cm−1, the antisymmetric stretching mode at 813 cm−1 and the deformation mode at 449 cm−1 to be calculated. The Raman spectrum of leiteite shows bands at 804 and 763 cm−1 assigned to the As2O42− symmetric and antisymmetric stretching modes. The most intense Raman band of leiteite is the band at 457 cm−1 and is assigned to the ν2 As2O42− bending mode. A comparison of the Raman spectrum of leiteite is made with the arsenite minerals reinerite and cafarsite. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

14.
    
The mixed anion mineral dixenite has been studied by Raman spectroscopy, complemented with infrared spectroscopy. The Raman spectrum of dixenite shows bands at 839 and 813 cm−1 assigned to the (AsO3)3− symmetric and antisymmetric stretching modes. The most intense Raman band of dixenite is the band at 526 cm−1 and is assigned to the ν2 AsO33− bending mode. DFT calculations enabled the calculation of the position of AsO22− symmetric stretching mode at 839 cm−1, the antisymmetric stretching mode at 813 cm−1, and the deformation mode at 449 cm−1. The Raman bands at 1026 and 1057 cm−1 are assigned to the SiO42− symmetric stretching vibrations and those at 1349 and 1386 cm−1 to the SiO42− antisymmetric stretching vibrations. Both Raman and infrared spectra indicate the presence of water in the structure of dixenite. This brings into question the commonly accepted formula of dixenite as CuMn2+14Fe3+(AsO3)5(SiO4)2(AsO4)(OH)6. The formula may be better written as CuMn2+14Fe3+(AsO3)5(SiO4)2(AsO4)(OH)6·xH2O. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

15.
    
Raman spectra of brandholzite Mg[Sb2(OH)12]·6H2O were studied, complemented with infrared spectra, and related to the structure of the mineral. An intense Raman sharp band at 618 cm−1 is attributed to the SbO symmetric stretching mode. The low‐intensity band at 730 cm−1 is ascribed to the SbO antisymmetric stretching vibration. Low‐intensity Raman bands were found at 503, 526 and 578 cm−1. Corresponding infrared bands were observed at 527, 600, 637, 693, 741 and 788 cm−1. Four Raman bands observed at 1043, 1092, 1160 and 1189 cm−1 and eight infrared bands at 963, 1027, 1055, 1075, 1108, 1128, 1156 and 1196 cm−1 are assigned to δ SbOH deformation modes. A complex pattern resulting from the overlapping band of the water and hydroxyl units is observed. Raman bands are observed at 3240, 3383, 3466, 3483 and 3552 cm−1; infrared bands at 3248, 3434 and 3565 cm−1. The Raman bands at 3240 and 3383 cm−1 and the infrared band at 3248 cm−1 are assigned to water‐stretching vibrations. The two higher wavenumber Raman bands observed at 3466 and 3552 cm−1 and two infrared bands at 3434 and 3565 cm−1 are assigned to the stretching vibrations of the hydroxyl units. Observed Raman and infrared bands in the OH stretching region are associated with O‐H···O hydrogen bonds and their lengths 2.72, 2.79, 2.86, 2.88 and 3.0 Å (Raman) and 2.73, 2.83 and 3.07 Å (infrared). Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

16.
We have studied the mineral kaliborite. The sample originated from the Inder B deposit, Atyrau Province, Kazakhstan, and is part of the collection of the Geology Department of the Federal University of Ouro Preto, Minas Gerais, Brazil. The mineral is characterized by a single intense Raman band at 756 cm?1 assigned to the symmetric stretching modes of trigonal boron. Raman bands at 1229 and 1309 cm?1 are assigned to hydroxyl in-plane bending modes of boron hydroxyl units. Raman bands are resolved at 2929, 3041, 3133, 3172, 3202, 3245, 3336, 3398, and 3517 cm?1. These Raman bands are assigned to water stretching vibrations. A very intense sharp Raman band at 3597 cm?1 with a shoulder band at 3590 cm?1 is assigned to the stretching vibration of the hydroxyl units. The Raman data are complimented with infrared data and compared with the spectrum of kaliborite downloaded from the Arizona State University database. Differences are noted between the spectrum obtained in this work and that from the Arizona State University database. This research shows that minerals stored in a museum mineral collection age with time. Vibrational spectroscopy enhances our knowledge of the molecular structure of kaliborite.  相似文献   

17.
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18.
    
The kaolinite‐like phyllosilicate minerals bismutoferrite BiFe3+2Si2O8(OH) and chapmanite SbFe3+2Si2O8(OH) have been studied by Raman spectroscopy and complemented with infrared spectra. Tentatively interpreted spectra were related to their molecular structure. The antisymmetric and symmetric stretching vibrations of the Si O Si bridges, δ SiOSi and δ OSiO bending vibrations, ν (Si Oterminal)− stretching vibrations, ν OH stretching vibrations of hydroxyl ions, and δ OH bending vibrations were attributed to the observed bands. Infrared bands in the range 3289–3470 cm−1 and Raman bands in the range 1590–1667 cm−1 were assigned to adsorbed water. O H···O hydrogen‐bond lengths were calculated from the Raman and infrared spectra. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

19.
    
Raman spectroscopy, complemented with infrared spectroscopy, was used to study the uranyl carbonate mineral voglite. The mineral has the formula Ca2Cu2+ [(UO2)(CO3)3](CO3)•6H2O, and bands attributed to these vibrating units are readily identified in the Raman spectrum. Symmetric stretching modes at 836 and 1094 cm−1 are assigned to ν1(UO2)2+ and ν1(CO3)2− units, respectively. The ν3 antisymmetric stretching modes of (UO2)2+ are not observed in the Raman spectrum but may be readily observed in the infrared spectrum at 898 cm−1. The ν3 antisymmetric stretching mode of (CO3)2− is observed in the Raman spectrum at 1369 cm−1 as a low intensity band as is also the ν3(CO3)2− infrared modes at 1362, 1425, 1509 and 1566 cm−1. No ν2(CO3)2− Raman bending modes are observed for voglite. The Raman band at 749 cm−1 and the two infrared bands at 747 and 709 cm−1 are assigned to the ν4(CO3)2− bending modes. U O bond and O H…O bond lengths in the structure of voglite were inferred from the infrared and Raman spectra. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

20.
丁硕  刘玉龙  萧季驹 《物理学报》2005,54(9):4416-4421
对晶粒尺寸在4—80nm范围的纯SnO2纳米颗粒进行了拉曼散射研究.除了SnO2本征拉曼振动峰外,还有几个新的拉曼振动峰和波长在700nm左右的一个发光很强而且峰宽很大的荧光峰被观察到.结果所示,当纳米颗粒尺寸减小时,纳米SnO2颗粒的体相 特征拉曼峰变弱,而由缺陷,表面和颗粒尺寸引起的相关效应呈强势.晶粒尺寸在20nm左右是引起体相拉曼光谱变化的临界尺寸.晶粒尺寸在20nm以下,其体相拉曼峰的发生宽化和峰位移动,以及分别出现在位于571cm-1 的表面振动峰,位于351cm-1 处的界面峰和与表面吸附水分子及氢氧基团的N系列拉曼峰是纳米SnO颗粒的主要特征.这些结果反映了纳米颗粒的微结构变化与颗粒尺寸和表面效应以及它们之间相互作用的信息.关键词：２')\" href=\"#\">纳米SnO２拉曼光谱荧光光谱水分子的吸附  相似文献   

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