Matt L. Weier

Queensland University of Technology, Brisbane, Queensland, Australia

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Publications (102)156.54 Total impact

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    ABSTRACT: Raman at 298 and 77 K and infrared spectra of two samples of sodium-zippeite were studied and interpreted. UO bond lengths in uranyl were calculated and compared with those inferred from the X-ray single crystal structure data of a synthetic sodium-zippeite analogue. Hydrogen-bonding network in the studied samples is discussed. OH…O bond lengths were calculated and compared with those predicted from the X-ray single crystal structure analysis. Copyright © 2007 John Wiley & Sons, Ltd.
    Journal of Raman Spectroscopy 09/2007; 38(10):1311 - 1319. · 2.68 Impact Factor
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    ABSTRACT: Raman spectra at 298 and 77K and infrared spectra of the uranyl sulfate mineral zippeite from Jáchymov (Joachimsthal), Czech Republic, K(0.6)(H(3)O)0.4[(UO(2))6(SO(4))3(OH)7].8H2O, were studied. Observed bands were tentatively attributed to the (UO(2))2+ and (SO(4))2- stretching and bending vibrations, the OH stretching vibrations of water molecules, hydroxyls and oxonium ions, and H(2)O, oxonium, and delta U-OH bending vibrations. Empirical relations were used for the calculation of U-O bond lengths in uranyl R (A)=f(nu(3) or nu(1)(UO(2))2+). Calculated U-O bond lengths are in agreement with U-O bond lengths from the single crystal structure analysis and those inferred for uranyl anion sheet topology of uranyl pentagonal dipyramidal coordination polyhedra. The number of observed bands supports the conclusion from single crystal structure analysis that at least two symmetrically distinct U6+ (in uranyls) and S6+ (in sulfates), water molecules and hydroxyls may be present in the crystal structure of the zippeite studied. Strong to very weak hydrogen bonds present in the crystal structure of zippeite studied were inferred from the IR spectra.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 09/2007; 67(5):1220-7. · 1.98 Impact Factor
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    Ray L Frost, Matt L Weier, Stuart J Mills
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    ABSTRACT: The silico-phosphate mineral perhamite has been studied using a combination of electron and vibrational spectroscopy. SEM photomicrographs reveal that perhamite morphology consists of very thin intergrown platelets that can form a variety of habits. Infrared spectroscopy in the hydroxyl-stretching region shows a number of overlapping bands which are observed in the range 3581-3078 cm(-1). These wavenumbers enable an estimation to be made of the hydrogen bond distances in perhamite: 3.176(0), 2.880(5), 2.779(6), 2.749(3), 2.668(1) and 2.599(7)A. Intense Raman bands are observed in the region 1110-1130 and 966-996 cm(-1) and are assigned to the SiO(4) and PO(4) symmetric stretching modes. Other bands are observed in the range 1005-1096 cm(-1) and are attributed to the nu(3) antisymmetric bending modes of PO(4). Some low intensity bands around 874 cm(-1) were discovered and remain unclassified. Bands in the low-wavenumber region are assigned to the nu(4) and nu(2) out-of-plane bending modes of the OSiO and PO(4) units. Raman spectroscopy is a useful tool in determining the vibrational spectroscopy of mixed hydrated multi-anion minerals such as perhamite. Information on such a mineral would be difficult to obtain by other means.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 08/2007; 67(3-4):604-10. · 1.98 Impact Factor
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    ABSTRACT: Raman spectroscopy at 298 and 77 K of bergenite has been used to characterise this uranyl phosphate mineral. Bands at 995, 971 and 961 cm-1 (298 K) and 1006, 996, 971, 960 and 948 cm-1 (77K) are assigned to the nu1(PO4)3- symmetric stretching vibration. Three bands at 1059, 1107 and 1152 cm-1 (298 K) and 1061, 1114 and 1164 cm-1 (77 K) are attributed to the nu3(PO4)3- antisymmetric stretching vibrations. Two bands at 810 and 798 cm-1 (298 K) and 812 and 800 cm-1 (77 K) are attributed to the nu1 symmetric stretching vibration of the (UO2)2+ units. Bands at 860 cm-1 (298 K) and 866 cm-1 (77 K) are assigned to the nu3 antisymmetric stretching vibrations of the (UO2)2+ units. UO bond lengths in uranyls, calculated using the wavenumbers of the nu1 and nu3(UO2)2+ vibrations with empirical relations by Bartlett and Cooney, are in agreement with the X-ray single crystal structure data. Bands at (444, 432, 408 cm-1) (298 K), and (446, 434, 410 and 393 cm-1) (77 K) are assigned to the split doubly degenerate nu2(PO4)3- in-plane bending vibrations. The band at 547 cm-1 (298 K) and 549 cm-1 (77 K) are attributed to the nu4(PO4)3- out-of-plane bending vibrations. Raman bands at 3607, 3459, 3295 and 2944 cm-1 are attributed to water stretching vibrations and enable the calculation of hydrogen bond distances of >3.2, 2.847, 2.740 and 2.637 A. These bands prove the presence of structurally nonequivalent hydrogen bonded water molecules in the structure of bergenite.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 04/2007; 66(4-5):979-84. · 1.98 Impact Factor
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    ABSTRACT: Uranopilite, [(UO2)6(SO4)O2(OH)6(H2O)6](H2O)8, the composition of which may vary, can be understood as a complex hydrated uranyl oxyhydroxy sulfate. The structure of uranopilite from different locations has been studied by Raman spectroscopy at 298 and 77 K. A single intense band at 1009 cm−1 assigned to the ν1 (SO4)2− symmetric stretching mode shifts to higher wavenumbers at 77 K. Three low-intensity bands are observed at 1143, 1117 and 1097 cm−1. These bands are attributed to the (SO4)2− ν3 anti-symmetric stretching modes. Multiple bands provide evidence that the symmetry of the sulfate anion in the uranopilite structure is lowered. Three bands are observed in the region 843 to 816 cm−1 in both the 298 and 77 K spectra and are attributed to the ν1 symmetric stretching modes of the (UO2)2+ units. Multiple bands prove the symmetry reduction of the UO2 ion. Multiple OH stretching modes prove a complex arrangement of OH groupings and hydrogen bonding in the crystal structure. A series of infrared bands not observed in the Raman spectra are found at 1559, 1540, 1526 and 1511 cm−1 attributed to δ UOH bending modes. U-O bond lengths in uranyl and OH/dotbondO bond lengths are calculated and compared with those from X-ray single crystal structure analysis. The Raman spectra of uranopilites of different origins show subtle differences, proving that the spectra are origin- and sample-dependent. Hydrogen-bonding network and its arrangement in the crystal structure play an important role in the origin and stability of uranopilite. Copyright © 2006 John Wiley & Sons, Ltd.
    Journal of Raman Spectroscopy 03/2007; 38(4):398 - 409. · 2.68 Impact Factor
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    Ray L. Frost, Jiří Čejka, Matt L. Weier
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    ABSTRACT: Raman and infrared spectra of five uranyl oxyhydroxide hydrates, becquerelite, billietite, curite, schoepite and vandendriesscheite, are reported. The observed bands are attributed to the (UO2)2+ stretching and bending vibrations, UOH bending vibrations and H2O and (OH)− stretching, bending and libration modes. The UO bond lengths in uranyls and the OH···O bond lengths are calculated from the wavenumbers assigned to the stretching vibrations. They are close to the values inferred and/or predicted from the X-ray single-crystal structure. The complex hydrogen-bonding network arrangement was proved in the structures of all the minerals studied. This hydrogen bonding contributes to the stability of these uranyl minerals. Copyright © 2006 John Wiley & Sons, Ltd. John Wiley & Sons, Ltd.
    Journal of Raman Spectroscopy 03/2007; 38(4):460 - 466. · 2.68 Impact Factor
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    ABSTRACT: Two sulphate efflorescent evaporite mineral samples from Jaroso, Spain have been studied by scanning electron microscopy and Raman spectroscopy. SEM by comparison with known minerals shows the evaporite mineral is a mixture of halotrichite and jarosite, whilst the oxidised mineral is predominantly jarosite. SEM characterises the halotrichite as long narrow crystals and the jarosite as distorted rhombohedral crystals. Raman spectra of the sulphates of K, Mg, Fe(II), Fe(III) are compared with the spectra of halotrichite, jarosite and the two sulphate efflorescent samples. The efflorescent sample was proven by Raman spectroscopy to be a mixture of halotrichite and jarosite and the oxidised efflorescent sample to be jarosite and a complex mixture of sulphates.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 02/2007; 66(1):177-83. · 1.98 Impact Factor
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    ABSTRACT: Raman and infrared spectroscopy has enabled insights into the molecular structure of the sampleite group of minerals. These minerals are based upon the incorporation of either phosphate or arsenate with chloride anion into the structure and as a consequence the spectra refect the bands attributable to these anions, namely phosphate or arsenate with chloride. The sampleite vibrational spectrum reflects the spectrum of the phosphate anion and consists of ν1 at 964, ν2 at 451 cm-1, ν3 at 1016 and 1088 and ν4 at 643, 604, 591 and 557 cm-1. The lavendulan spectrum consists of ν1 at 854, ν2 at 345 cm-1, ν3 at 878 cm-1 and ν4 at 545 cm-1. The Raman spectrum of lemanskiite is different from that of lavendulan consistent with a different structure. Low wavenumber bands at 227 and 210 cm-1 may be assigned to CuCl TO/LO optic vibrations. Raman spectroscopy identified the substitution of arsenate by phosphate in zdenekite and lavendulan.
    Journal of Raman Spectroscopy 01/2007; · 2.68 Impact Factor
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    ABSTRACT: Raman and infrared spectra of the uranyl oxyhydroxide hydrate: curite is reported. Observed bands are attributed to the (UO2)2+ stretching and bending vibrations, U-OH bending vibrations, H2O and (OH)- stretching, bending and librational modes. U-O bond lengths in uranyls and O-H…O bond lengths are calculated from the wavenumbers assigned to the stretching vibrations. These bond lengths are close to the values inferred and/or predicted from the X-ray single crystal structure. The complex hydrogen-bonding network arrangement was proved in the structures of the curite minerals. This hydrogen bonding contributes to the stability of these uranyl minerals.
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    ABSTRACT: A Ni-Co-As ore sample from Cobalt City, Ontario, Canada, was examined with scanning electron microscopy and energy dispersive X-ray analysis. In addition to cobaltian pararammelsbergite with variable cobalt content, for which Cobalt City is the type locality, and erythrite, one new mineral was observed for this locality. Well-formed crystals of arsenolite, As(2)O(3), were found embedded in what appears to be fibrous spherocobaltite, CoCO(3). Additional information was obtained by Raman microscopy, confirming the identification of the arsenolite. Both are considered to be secondary minerals formed by exposure to air resulting in oxidation and the formation of secondary carbonates.
    Applied Spectroscopy 12/2006; 60(11):1293-6. · 1.94 Impact Factor
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    Ray L Frost, Jirí Cejka, Matt Weier
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    ABSTRACT: Raman spectra of threadgoldite at 298 and 77K are measured and interpreted for the first time. Bands related the (UO(2))(2+) and (PO(4))(3-) stretching and bending vibrations are tenatively attributed together with the bands assigned to the stretching a and bending vibrations of water molecules and hydroxyls. Hydrogen-bonding network and H(2)O and (OH)(-1) libration modes are mentioned. U-O bond lengths in uranyls are calculated via empirical relations R(U-O)=f[nu(1) and nu(3)(UO(2))(2+)]A. They are comparable to the values inferred from the single crystal structure analysis of threadgoldite.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 12/2006; 65(3-4):797-801. · 1.98 Impact Factor
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    Ray L Frost, Matt Weier
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    ABSTRACT: The mineral allactite [Mn(7)(AsO(4))(2)(OH)(8)] is a basic manganese arsenate which is highly pleochroic. The use of the 633 nm excitation line enables quality spectra of to be obtained irrespective of the crystal orientation. The mineral is characterised by a set of sharp bands in the 770-885 cm(-1) region. Intense and sharp Raman bands are observed at 883, 858, 834, 827, 808 and 779 cm(-1). Collecting the spectral data at 77K enabled better band separation with narrower bandwidths. The observation of multiple AsO(4) stretching bands indicates the non-equivalence of the arsenate anions in the allactite structure. In comparison the infrared spectrum shows a broad spectral profile with a series of difficult to define overlapping bands. The low wavenumber region sets of bands which are assigned to the nu(2) modes (361 and 359 cm(-1)), the nu(4) modes (471, 452 and 422 cm(-1)), AsO stretching vibrations at 331 and 324 cm(-1), and bands at 289 and 271 cm(-1) which may be ascribed to MnO stretching modes. The observation of multiple bands shows the loss of symmetry of the AsO(4) units and the non-equivalence of these units in the allactite structure. The study shows that highly pleochroic minerals can be studied by Raman spectroscopy.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 12/2006; 65(3-4):623-7. · 1.98 Impact Factor
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    ABSTRACT: Raman spectroscopy at 298 and 77K has been used to study the mineral kamotoite-(Y), a uranyl rare earth carbonate mineral of formula Y(2)(UO(2))(4)(CO(3))(3)(OH)(8).10-11H(2)O. The mineral is characterised by two Raman bands at 1130.9 and 1124.6 cm(-1) assigned to the nu(1) symmetric stretching mode of the (CO(3))(2-) units, while those at 1170.4 and 862.3 cm(-1) (77K) to the deltaU-OH bending vibrations. The assignment of the two bands at 814.7 and 809.6 cm(-1) is difficult because of the potential overlap between the symmetric stretching modes of the (UO(2))(2+) units and the nu(2) bending modes of the (CO(3))(2-) units. Only a single band is observed in the 77K spectrum at 811.6 cm(-1). One possible assignment is that the band at 814.7 cm(-1) is attributable to the nu(1) symmetric stretching mode of the (UO(2))(2+) units and the second band at 809.6 cm(-1) is due to the nu(2) bending modes of the (CO(3))(2-) units. Bands observed at 584 and 547.3 cm(-1) are attributed to water librational modes. An intense band at 417.7 cm(-1) resolved into two components at 422.0 and 416.6 cm(-1) in the 77K spectrum is assigned to an Y(2)O(2) stretching vibration. Bands at 336.3, 286.4 and 231.6 cm(-1) are assigned to the nu(2) (UO(2))(2+) bending modes. U-O bond lengths in uranyl are calculated from the wavenumbers of the uranyl symmetric stretching vibrations. The presence of symmetrically distinct uranyl and carbonate units in the crystal structure of kamotoite-(Y) is assumed. Hydrogen-bonding network related to the presence of water molecules and hydroxyls is shortly discussed.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 12/2006; 65(3-4):529-34. · 1.98 Impact Factor
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    ABSTRACT: Raman spectra of schmitterite measured at 298 and 77K are presented and discussed in detail and in part in comparison with published IR spectrum of synthetic schmitterite. U-O bond lengths in uranyls, calculated with the empirical relations R(U-O)=f[nu(1)(UO(2))(2+)]A and R(U-O)=f[nu(3)(UO(2))(2+)] A, are close to those inferred from the X-ray single crystal structure of synthetic schmitterite and agree also with the data for other natural and synthetic uranyl tellurites.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 12/2006; 65(3-4):571-4. · 1.98 Impact Factor
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    ABSTRACT: Raman spectra of two samples of the uranyl mineral dewindtite are presented and interpreted. The observed bands are attributed to the stretching and bending vibrations of the (UO2)2+ and (PO4)3− units and water molecules. The hydrogen-bonding network in the dewindtite crystal structure is briefly mentioned. The UO bond lengths in uranyls were calculated with empirical relations and wavenumbers of the (UO2)2+ stretching vibrations. These calculations are in agreement with the X-ray single crystal structure data. Copyright © 2006 John Wiley & Sons, Ltd.
    Journal of Raman Spectroscopy 11/2006; 37(12):1362 - 1367. · 2.68 Impact Factor
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    ABSTRACT: The thermal decompositions of hydrotalcites with hexacyanoferrate(II) and hexacyanoferrate(III) in the interlayer have been studied using thermogravimetry combined with mass spectrometery. X-ray diffraction shows the hydrotalcites have a d(003) spacing of 11.1 and 10.9 Å which compares with a d-spacing of 7.9 and 7.98 Å for the hydrotalcite with carbonate or sulphate in the interlayer. XRD was also used to determine the products of the thermal decomposition. For the hydrotalcite decomposition the products were MgO, Fe2O3 and a spinel MgAl2O4. Dehydration and dehydroxylation take place in three steps each and the loss of cyanide ions in two steps.
    Journal of Thermal Analysis and Calorimetry 09/2006; · 1.98 Impact Factor
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    ABSTRACT: The mineral parsonsite, with samples from The Ranger Uranium Mine, Australia, and the La Faye Mine, Grury, Saone-et-Loire, Burgundy, France, has been characterised by Raman spectroscopy at 298 and 77 K and complemented with infrared spectroscopy. Two Raman bands close to 807 and 796 cm−1 are attributed to the ν1(UO2)2+ symmetric stretching modes, while two bands close to 953 or 945 cm−1 and 863–873 cm−1 are assigned to the ν3(UO2)2+ anti-symmetric stretching vibrations. Four or five bands (953, 926, 910, 883 cm−1) are observed in the infrared spectrum in this region. Bands at 965–967 and 972 cm−1 are assigned to the ν1(PO4)3− symmetric stretching modes and bands that are observed in the 987 to 1078 cm−1region to the ν3(PO4)3− anti-symmetric stretching modes. Bands at 465, 439, 406, 394 cm−1 (298 K) and 466, 442, 405, 395 cm−1(77 K) are assigned to the split, doubly degenerate ν2(PO4)−3bending vibrations. Bands of very low intensity at 609, 595, 591, 582, 560 and 540 cm−1are attributed to the split, triply degenerate ν4(PO4)−3bending modes. Bands observed at wavenumbers lower than 300 cm−1are connected with the split ν2(δ) (UO2)2+ bending, ν(UOligand), δ(UOligand) and lattice vibrations. UO bond lengths in uranyl were calculated from the Raman and infrared spectra, which are in agreement with those from the available X-ray single crystal structure analysis of parsonsite. A short comment is given on the water content and the possibility of a hydrogen-bonding network in the parsonsite crystal structure. Copyright © 2006 John Wiley & Sons, Ltd.
    Journal of Raman Spectroscopy 08/2006; 37(9):879 - 891. · 2.68 Impact Factor
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    ABSTRACT: The mineral haynesite, a uranyl selenite, has been characterised by Raman spectroscopy at 298 and 77 K. Two bands at 811.5 and 800.2 cm−1 are assigned to the symmetric stretching modes of the (UO2)2+ and (SeO3)2− units respectively. These values give calculated UO bond lengths of 1.799 and/or 1.801 Å. The broad band at 861.8 cm−1 is assigned to the ν3 antisymmetric stretching mode of the (UO2)2+ (calculated UO bond length 1.813 Å). Additional bands are observed in the 77 K spectrum. In the spectroscopy of selenite compounds, the position of the antisymmetric stretching vibration occurs at lower wavenumbers than the symmetric stretching mode and thus the band at 740.5 cm−1 is attributed to the ν3 antisymmetric stretching vibration of the (SeO3)2− units. The ν4 and the ν2 vibrational modes of the (SeO3)2− units are observed at 418.5 and 472.1 cm−1. Bands observed at 278.3, 257.3 and 218.8 cm−1 are assigned to OUO bending vibrations. Copyright © 2006 John Wiley & Sons, Ltd.
    Journal of Raman Spectroscopy 07/2006; 37(8):816 - 821. · 2.68 Impact Factor
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    ABSTRACT: Raman spectroscopy has been used to study the molecular structure of a series of selected uranyl silicate minerals, including weeksite K2[(UO2)2(Si5O13)].H2O, soddyite [(UO2)2SiO4.2H2O] and haiweeite Ca[(UO2)2(Si5O12(OH)2](H2O)3 with UO2(2+)/SiO2 molar ratio 2:1 or 2:5. Raman spectra clearly show well resolved bands in the 750-800 cm-1 region and in the 950-1000 cm-1 region assigned to the nu1 modes of the (UO2)2+ units and to the (SiO4)4- tetrahedra. For example, soddyite is characterized by Raman bands at 828.0, 808.6 and 801.8 cm-1 (UO2)2+ (nu1), 909.6 and 898.0 cm-1 (UO2)2+ (nu3), 268.2, 257.8 and 246.9 cm-1 are assigned to the nu2 (delta) (UO2)2+. Coincidences of the nu1 (UO2)2+ and the nu1 (SiO4)4- is expected. Bands at 1082.2, 1071.2, 1036.3, 995.1 and 966.3 cm-1 are attributed to the nu3 (SiO4)4-. Sets of Raman bands in the 200-300 cm-1 region are assigned to nu2 (delta) (UO2)2+ and UO ligand vibrations. Multiple bands indicate the non-equivalence of the UO bonds and the lifting of the degeneracy of nu2 (delta) (UO2)2+ vibrations. The (SiO4)4- tetrahedral are characterized by bands in the 470-550 cm-1 and in the 390-420 cm-1 region. These bands are attributed to the nu4 and nu2 (SiO4)4- bending modes. The minerals show characteristic OH stretching bands in the 2900-3500 cm-1 and 3600-3700 cm-1.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 06/2006; 64(2):308-15. · 1.98 Impact Factor
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    ABSTRACT: Raman spectra at 298 and 77 K of three uranophane samples from different localities are described and interpreted. The spectra are sample dependent. U–O bond lengths in uranyls are calculated from the spectra and compared with the published data of single crystal structure and EXAFS spectroscopy. Hydrogen-bonding of water molecules and silanols is discussed and the ‘proton mobility’ in uranophane sheet crystal structure is assumed.
    Journal of Molecular Structure 05/2006; · 1.40 Impact Factor