The compression behavior of iron oxyhydroxide ε-FeOOH is complex, with variations in its magnetic property and bonding character. In this study, situ powder neutron diffraction experiments were conducted on ε-FeOOD up to pressures exceeding 20 GPa investigate a spin-reorientation (spin-flop) transition, hydrogen-bond (H-bond) symmetrization, their correlation. transition was observed at 8 both ε-FeOOD. Fe-spins aligned an A-type antiferromagnetic order reoriented from the c-direction...

Gold (or electrum) in hydrothermal fluid precipitates directly from gold sulfide complex and/or partly via suspended nanoparticles. The contains “invisible gold” that is atomically dispersed minerals or as nanoparticles with a size of less than 10 nm. However, the contribution these to formation native and its alloy silver (electrum) remains unclear. Higashi–Aogashima Knoll Caldera field, south Tokyo, Japan, an area significant seafloor activity known for high-grade gold-containing...

The single-crystal synchrotron study of the high-pressure modification aluminium oxide hydroxide, δ-AlOOH, confirms previous structure determination in space group P21nm, which was based on X-ray powder data [Suzuki, Ohtani & Kamada (2000). Phys. Chem. Miner. 27, 689–693]. present includes H-atom parameters, revealed a strong asymmetric hydrogen bond with an O⋯O distance 2.5479 (12) Å. δ-AlOOH is isotypic that β-CrOOH and may be considered as distorted rutile type all atoms located mirror planes.

Chiral symmetry breaking in NaClO3 crystallization from an aqueous solution with perturbations has been of great interest. To understand the mechanism, several models focusing on early stage have proposed. However, they are ambiguous because barely explored directly. Here, we investigate stages process driven by droplet evaporation using a combination direct situ microscopic observations and cryogenic single-crystal XRD experiments. We demonstrate that achiral crystal having P21/a symmetry,...

Inelastic X-ray scattering (IXS) measurements have been performed on an MgO single crystal in order to evaluate IXS as a methodology for accurate and precise determination of elastic constants sound velocities. By performing the experiment using 12-analyzer array, complete set single-crystal were determined precision better than 0.8% (sound velocities 0.2%). The results are consistent with values literature. accuracy this work, which is significantly other published work date, demonstrates...

The presence of water in the Earth's deep mantle is an issue increasing interest field highpressure mineralogy. An important task for further advancing research to create homogeneous single crystals candidate deep-mantle water-bearing minerals 1 mm or larger size, which required applying them time-of-flight (TOF) single-crystal Laue diffraction method with a third-generation neutron instrument. In this study, we perform several experiments demonstrate improved methodology growing hydrous...

Theoretical and experimental research, on the previously unresolved instability occurring along slip stream of a shock-wave Mach reflection, is presented. Growth rates large-scale Kelvin-Helmholtz shear flow are used to model evolution slip-stream in ideal gas, thus indicating secondary small-scale growth as cause for thickening. The validated through experiments measuring range numbers reflection wedge angles. Good agreement found Reynolds Re 2 x 10(4). This work demonstrates, first time,...

The crystal structure of a single synthetic hydrous forsterite, (Mg1.985Si0.993H0.06O4), synthesized at T = 1300 °C and P 13.5 GPa has been investigated using X-ray diffractometry unpolarized infrared absorption spectroscopy. data show an Mg atom occupancy 98.6(2)% the M(1) site 99.9(2)% M(2) site, indicating that cation vacancies predominantly occur site. A comparison calculated bond distances shows most probable H locations are O(2) O(3) sites, where may be located in association with...

The effect of temperature and pressure was analyzed on the crystal structure natural topaz from Gilgit division, Pakistan. unit cell parameters at 298K, 423K, 573K, 723K, 873K, 1023K 1173K, X-ray diffraction intensity data 873K 1173K were collected using an imaging plate diffractometer equipped with rotating anode generator. Thermal expansion coefficients along edges volume are αa=6.4(7)×10-6K-1, αb=5.5(6) ×10-6K-1, αc=8.1(6) ×10-6K-1 αV =2.0(1) ×10-5K-1. results refinement taking into...

OH stretching vibration modes for F-rich natural topaz (F-topaz) and fully hydrated (topaz-OH) synthesized at high pressure, were observed using IR Raman spectroscopies pressures up to 30.4 GPa 17.3 GPa, respectively. In F-topaz, the pressure derivative of frequency band 3650 cm-1 ambient was 0.91(3) cm-1/GPa, which consistent with value recently reported by Bradbury Williams (2003). On other hand, in topaz-OH, derivatives bands initially 3599 3522 -5.2(2) -2.56(6) This contrasting behavior...

X-ray diffraction intensities were measured for single-crystal, spinel structure ringwoodite (γ-Mg1.97SiH0.03O4) at pressures up to 7.9 GPa in the BL-10A synchrotron beam line of Photon Factory. The isothermal bulk modulus calculated using Birch-Murnaghan equation state assuming KT' = 4 was KT 184(6) GPa. difference between this result and value anhydrous is not significant within limit experimental error due a minimal H2O content. oxygen positional parameter u revealed increase...

Abstract Phase relations of Al 2 SiO 5 have been studied by multianvil experiments at pressures 13–23 GPa and temperatures 2000–2900 K. kyanite was found to transform into two new high‐pressure forms (kyanite II III) exceeding 2300–2500 K 14–23 GPa: The first phase transition occurs near 14 GPa, the second 17 GPa. phases triclinic monoclinic crystal symmetries with zero‐pressure densities 3.876(2) 3.982(1) g/cm 3 , respectively, which are significantly denser than ( ρ 0 = 3.666 ) but less...

A neutron powder diffraction study was performed to determine the sites occupied by hydrogen in structure of DHMS phase G, which is stable at pressure‐temperature conditions transition zone and lower mantle. The data from small samples (about 3 mg) were collected using a highly sensitive imaging plate detector BIX‐3 beamline JRR‐3M nuclear plant JAERI Tokai Laboratory, Japan. present reveal that (and deuterium) located 6k site Wykoff letter MO 6 layer G with space group . bond lengths O‐H...

Crystals of liddicoatite-elbaite tourmaline from a pegmatite in Jochy, Madagascar are composed o{021̄1}, r{101̄1}, c{0001}, a{112̄̄0}, and m{101̄0} sectors, which correspond to the prominent crystal faces, respectively. Therefore, sectors were produced during growth, not by strain after growth. The o, m, r one specimen biaxial between crossed polars [2V(-) = 30°, 20°, 15°, respectively] triclinic, as indicated X-ray diffraction. sector is optically orthorhombic. c uniaxial essentially...

The high-pressure phase of gibbsite has been studied by in situ single crystal X-ray diffraction method and molecular dynamics (MD) simulation at 3.0 GPa. structure the phase, η -Al(OH) 3 , was successfully determined direct methods based on intensities diffraction. space group lattice constants for are P 2 1 / b 11 (#14), a = 8.612(3) Å, 5.013(2) c 9.194(5) Å α 90.34(6)°, respectively. consists an Al octahedral layer, layers connected via H-bonds. mechanism transition from to is also...

High-pressure single crystal X-ray diffraction studies of a natural chondrodite, Mg4.76Fe0.22Ti0.02Si1.99O8(OH1.26F0.74), and synthetic OH-chondrodite, Mg4.98Si2.01H2.00O10, were performed using diamond anvil cell (DAC) up to 7.3 5.9 GPa, respectively at room temperature. FT-IR spectra the chondrodite under high-pressure conditions 9.9 GPa was also observed DAC. The axial linear compressibilities these samples are calculated as βa = 1.69(4) × 10−3, βb 2.98(4) 10−3 βc 2.74(5) (GPa−1) for...

In situ high-temperature crystal structure analysis of natural heulandite with the chemical composition (Na1.14K0.40Ca3.64Sr0.21)(Al9.21Si26.88)O72·25.2H2O from Maharastra, India was conducted up to 300 °C. The room-temperature and X-ray diffraction intensities a single were measured using an imaging plate detector coupled U-shaped furnace. At room temperature, sample monoclinic, C2/m symmetry [a = 17.716(4) Å, b 17.880(3) c 7.438(2) β 116.43(1)°]. Structural refinement data set at...

Tanohataite, LiMn2Si3O8(OH), the Li analogue of serandite, has been found in a metamorphosed manganese ore deposit Tanohata mine, Iwate Prefecture, Japan. The mineral triclinic space group P1 with = 7.612(7), b 7.038(4), c 6.700(4) Å, α 90.23(6)°, β 94.70(7)°, γ 105.26 (8)°, V =345.0(3) Å3, and Z 2. seven strongest lines X-ray powder diffraction pattern are [d(Å), (I), (hkl)]: 6.64(35)(001), 3.67(26)(200), 3.13(89)(102), 3.11(69)(211), 2.95(100)(102), 2.81(33)(120), 2.18(40)(103). Electron...