Infrared reflectance of single-crystal jarandolite, CaB3O4(OH)3

2007 ◽  
Vol 71 (3) ◽  
pp. 273-283
Author(s):  
P. M. Nikolić ◽  
S. Đurić ◽  
K. M. Paraskevopoulos ◽  
T. T. Zorba ◽  
D. Luković ◽  
...  
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
New Mineral ◽  
Vibration Modes ◽  
Infrared Reflectance ◽  
Lorentz Model ◽  
Mid Infrared ◽  
New Mineral Species ◽  
Principal Directions ◽  
Mode Assignment

AbstractPolarized far- and mid-infrared reflectance spectra were measured at room temperature for the new mineral species jarandolite, CaB3O4(OH)3, for the two principal directions. Thirty three vibration modes for and 32 for were observed and analysed numerically. Symmetry analysis predicts 41 and 40 vibration modes that include lattice and O–H modes. Mode assignment was made based on the structure of jarandolite. The values of the mode frequencies (ωTO), the damping factors (γ) and the oscillator strength (S) of each oscillator were obtained by fitting to a Lorentz model.

Hylbrownite, Na3MgP3O10·12H2O, a new triphosphate mineral from the Dome Rock Mine, South Australia: description and crystal structure

2013 ◽  
Vol 77 (3) ◽  
pp. 385-398 ◽  
Author(s):  
P. Elliott ◽  
J. Brugger ◽  
T. Caradoc-Davies ◽  
A. Pring
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
South Australia ◽  
New Mineral ◽  
Monoclinic Space Group ◽  
Thick Sheet ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Mineral Species ◽  
Mohs Hardness

AbstractHylbrownite, ideally Na3MgP3O10·12H2O, the second known triphosphate mineral, is a new mineral species from the Dome Rock mine, Boolcoomatta Reserve, Olary Province, South Australia, Australia. The mineral forms aggregates and sprays of crystals up to 0.5 mm across with individual crystals up to 0.12 mm in length and 0.02 mm in width. Crystals are thin prismatic to acicular in habit and are elongate along [001]. Forms observed are {010}, {100}, {001}, {210} and {201}. Crystals are colourless to white, possess a white streak, are transparent, brittle, have a vitreous lustre and are nonfluorescent. The measured density is 1.81(4) g cm−3; Mohs' hardness was not determined. Cleavage is good parallel to {001} and to {100} and the fracture is uneven. Hylbrownite crystals are nonpleochroic, biaxial (−), with α = 1.390(4), β = 1.421(4), γ = 1.446(4) and 2Vcalc. = 82.2°. Hylbrownite is monoclinic, space group P21/n, with a = 14.722(3), b = 9.240(2), c = 15.052(3) Å, β = 90.01(3)°, V = 2047.5(7) Å3, (single-crystal data) and Z = 4. The strongest lines in the powder X-ray diffraction pattern are [d (Å)(I)(hkl)]: 10.530(60)(10,101), 7.357(80)(200), 6.951(100)(11, 111), 4.754(35)(10, 103), 3.934(40)(022), 3.510(45)(30, 303), 3.336(35)(41, 411). Chemical analysis by electron microprobe gave Na2O 16.08, MgO 7.08, CaO 0.43, P2O5 37.60, H2Ocalc 38.45, total 99.64 wt.%. The empirical formula, calculated on the basis of 22 oxygen atoms is Na2.93Mg0.99Ca0.04P2.99O9.97·12.03H2O. The crystal structure was solved from single-crystal X-ray diffraction data using synchrotron radiation (T = 123 K) and refined to R1 = 4.50% on the basis of 2417 observed reflections with F0 > 4 σ(F0). [Mg(H2O)3P3O10] clusters link in the b direction to Naφ6 octahedra, by face and corner sharing. Edge sharing Naφ6 Octahedra and Naφ7 polyhedra form Na2O9 groups which link via corners to form chains along the b direction. Chains link to [Mg(H2O)3P3O10] clusters via corner-sharing in the c direction and form a thick sheet parallel to (100). Sheets are linked in the a direction via hydrogen bonds.

Smamite, Ca2Sb(OH)4[H(AsO4)2]·6H2O, a new mineral and a possible sink for Sb during weathering of fahlore

2020 ◽  
Vol 105 (4) ◽  
pp. 555-560
Author(s):  
Jakub Plášil ◽  
Anthony R. Kampf ◽  
Nicolas Meisser ◽  
Cédric Lheur ◽  
Thierry Brunsperger ◽  
...  
Keyword(s):  
White Light ◽  
Electron Microprobe ◽  
Room Temperature ◽  
New Mineral ◽  
Calculated Density ◽  
New Mineral Species ◽  
Mohs Hardness ◽  
Measured Density ◽  
Ore District ◽  
The Ideal

Abstract Smamite, Ca2Sb(OH)4[H(AsO4)2]·6H2O, is a new mineral species from the Giftgrube mine, Rauenthal, Sainte-Marie-Aux-Mines ore-district, Haut-Rhin department, France. It is a supergene mineral found in quartz-carbonate gangue with disseminated to massive tennantite-tetrahedrite series minerals, native arsenic, Ni-Co arsenides, and supergene minerals picropharmacolite, fluckite, and pharmacolite. Smamite occurs as lenticular crystals growing in aggregates up to 0.5 mm across. The new mineral is whitish to colorless, transparent with vitreous luster and white streak; non-fluorescent under UV radiation. The Mohs hardness iŝ3½; the tenacity is brittle, the fracture is curved, and there is no apparent cleavage. The measured density is 2.72(3) g/cm3; the calculated density is 2.709 g/cm3 for the ideal formula. The mineral is insoluble in H2O and quickly soluble in dilute (10%) HCl at room temperature. Optically, smamite is biaxial (–), α = 1.556(1), β = 1.581(1), γ = 1.588(1) (white light). The 2V (meas) = 54(1)°; 2V (calc) = 55.1°. The dispersion is weak, r > ν. Smamite is non-pleochroic. Electron microprobe analyses provided the empirical formula Ca2.03Sb0.97(OH)4[H1.10(As1.99Si0.01O4)2]·6H2O. Smamite is triclinic, P1–, a = 5.8207(4), b = 8.0959(6), c = 8.21296(6) Å, α = 95.8343(7)°, β = 110.762(8)°, γ = 104.012(7)°, V = 402.57(5) Å3, and Z = 1. The structure (Robs = 0.027 for 1518 I>3σI reflections) is based upon {Ca2(H2O)6Sb(OH)4[H(AsO4)2]} infinite chains consisting of edge-sharing dimers of Ca(H2O)3O2(OH)2 polyhedra that share edges with Sb(OH)4O2 octahedra; adjacent chains are linked by H-bonds, including one strong, symmetrical H-bond with an O–H bond-length of ∼1.23 Å. The name “smamite” is based on the acronym of the Sainte-Marie-aux-Mines district.

scholarly journals VI. Description of Hopeite, a New Mineral, from Altenberg near Aix-la-Chapelle

1826 ◽  
Vol 10 (1) ◽  
pp. 107-111 ◽  
Author(s):  
David Brewster
Keyword(s):  
Single Crystal ◽  
Mineral Species ◽  
New Mineral ◽  
New Variety ◽  
New Mineral Species ◽  
The Family ◽  
Optical Structure

About the end of the year 1821, when I was engaged in the examination of the Family of the Zeolites, Mr Heuland was so obliging as to send me a variety of Stilbite from a Calamine mine at Altenberg near Aix-la-Chapelle. Upon comparing its optical structure with that of the Stilbites, it was manifest that it had no connection with this class of crystals, and that it constituted a new mineral species. Upon mentioning this result to Mr Brooke, this acute mineralogist was of opinion that it was the Silicate of Zinc. Mr Heuland had been led to regard this substance as a Stilbite, in consequence of having received it as such from Major Petersen; but, particularly, from finding in the collection of Mr C. H. Turner, a single crystal of the same substance attached to Carbonate of Zinc, and bearing the annexed figure, with an inscription in the handwriting of the Abbé Hauy, stating it to be a new variety of Stilbite, to which he gave the name of Stilbite Duovigesimale.

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

Mozartite, CaMn(OH)SiO 4 , a new mineral species from the Cerchiara Mine, northern Apennines, Italy

1993 ◽  
Vol 31 (2) ◽  
pp. 331-336 ◽  
Author(s):  
R. Brasso ◽  
G. Lucchetti ◽  
L. Zefiro ◽  
A. Palenzona
Keyword(s):  
Northern Apennines ◽  
Mineral Species ◽  
New Mineral ◽  
New Mineral Species

scholarly journals Old Donors for New Molecular Conductors: Combining TMTSF and BEDT-TTF with Anionic (TaF6)1−x/(PF6)x Alloys

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 386
Author(s):  
Magali Allain ◽  
Cécile Mézière ◽  
Pascale Auban-Senzier ◽  
Narcis Avarvari
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
Density Wave ◽  
Spin Density Wave ◽  
Orthorhombic Phase ◽  
Molecular Conductors ◽  
Bechgaard Salts ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
Resistivity Measurements

Tetramethyl-tetraselenafulvalene (TMTSF) and bis(ethylenedithio)-tetrathiafulvalene (BEDT-TTF) are flagship precursors in the field of molecular (super)conductors. The electrocrystallization of these donors in the presence of (n-Bu4N)TaF6 or mixtures of (n-Bu4N)TaF6 and (n-Bu4N)PF6 provided Bechgaard salts formulated as (TMTSF)2(TaF6)0.84(PF6)0.16, (TMTSF)2(TaF6)0.56(PF6)0.44, (TMTSF)2(TaF6)0.44(PF6)0.56 and (TMTSF)2(TaF6)0.12(PF6)0.88, together with the monoclinic and orthorhombic phases δm-(BEDT-TTF)2(TaF6)0.94(PF6)0.06 and δo-(BEDT-TTF)2(TaF6)0.43(PF6)0.57, respectively. The use of BEDT-TTF and a mixture of (n-Bu4N)TaF6/TaF5 afforded the 1:1 phase (BEDT-TTF)2(TaF6)2·CH2Cl2. The precise Ta/P ratio in the alloys has been determined by an accurate single crystal X-ray data analysis and was corroborated with solution 19F NMR measurements. In the previously unknown crystalline phase (BEDT-TTF)2(TaF6)2·CH2Cl2 the donors organize in dimers interacting laterally yet no organic-inorganic segregation is observed. Single crystal resistivity measurements on the TMTSF based materials show typical behavior of the Bechgaard phases with room temperature conductivity σ ≈ 100 S/cm and localization below 12 K indicative of a spin density wave transition. The orthorhombic phase δo-(BEDT-TTF)2(TaF6)0.43(PF6)0.57 is semiconducting with the room temperature conductivity estimated to be σ ≈ 0.16–0.5 S/cm while the compound (BEDT-TTF)2(TaF6)2·CH2Cl2 is also a semiconductor, yet with a much lower room temperature conductivity value of 0.001 to 0.0025 S/cm, in agreement with the +1 oxidation state and strong dimerization of the donors.

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