scholarly journals High-Pressure Raman Spectroscopy and X-ray Diffraction Study on Scottyite, BaCu2Si2O7

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 608
Author(s):  
Pei-Lun Lee ◽  
Eugene Huang ◽  
Jennifer Kung
Keyword(s):  
High Pressure ◽  
Vibration Modes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Diamond Anvil ◽  
Compression Data ◽  
Diffraction Patterns ◽  
Murnaghan Equation

In situ high-pressure synchrotron X-ray diffraction and Raman spectroscopic experiments of scottyite, BaCu2Si2O7, were carried out in a diamond anvil cell up to 21 GPa at room temperature. X-ray diffraction patterns reveal four new peaks near 3.5, 3.1, 2.6 and 2.2 Å above 8 GPa, while some peaks of the original phase disappear above 10 GPa. In the Raman experiment, we observed two discontinuities in dν/dP, the slopes of Raman wavenumber (ν) of some vibration modes versus pressure (P), at approximately 8 and 12 GPa, indicating that the Si-O symmetrical and asymmetrical vibration modes change with pressure. Fitting the compression data to Birch–Murnaghan equation yields a bulk modulus of 102 ± 5 GPa for scottyite, assuming Ko′ is four. Scottyite shows anisotropic compressibility along three crystallographic axes, among which c-axis was the most compressible axis, b-axis was the last and a-axis was similar to the c-axis on the compression. Both X-ray and Raman spectroscopic data provide evidences that scottyite undergoes a reversible phase transformation at 8 GPa.

HIGH-PRESSURE STRUCTURE STUDY OF CuBa2Ca3Cu4O10 + δ SUPERCONDUCTOR

2005 ◽  
Vol 19 (06) ◽  
pp. 313-316
Author(s):  
X. M. QIN ◽  
Y. YU ◽  
G. M. ZHANG ◽  
F. Y. LI ◽  
J. LIU ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Room Temperature ◽  
Diamond Anvil Cell ◽  
Structure Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diamond Anvil ◽  
Murnaghan Equation

In-situ high-pressure energy dispersive X-ray diffraction measurements on CuBa 2- Ca 3 Cu 4 O 10 + δ (Cu-1234) have been performed by using diamond anvil cell (DAC) device with synchrotron radiation. The results suggest that the crystal structure of Cu-1234 superconductor is stable under pressures up to 34 GPa at room temperature. According to the Birch–Murnaghan equation of state, the bulk modulus is obtained to be ~ 150 GPa.

scholarly journals Compressional behavior of strontianite SrCO3 by synchrotron X-ray radiation diffraction: effects of pressure transmitting media

2020 ◽  
Vol 48 (5-6) ◽  
pp. 455-467
Author(s):  
BO ZHANG ◽  
SHIJIE HUANG ◽  
WEI CHEN ◽  
BO LI ◽  
ZHILIN YE ◽  
...  
Keyword(s):  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Pressure Derivative ◽  
X Ray ◽  
Diamond Anvil ◽  
Pressure Unit ◽  
Diffraction Patterns ◽  
Diffraction Effects ◽  
Murnaghan Equation

The compressional behavior of strontianite SrCO3 was investigated at ambient temperature and high pressure, using a diamond anvil cell (DAC) with Ne as a pressure transmitting medium. X-ray diffraction patterns were collected to ~52 GPa using in situ angle-dispersive synchrotron-based powder X-ray diffraction (XRD). A phase transition was observed at ~20 GPa, and no indications of further transitions were detected up to ~52 GPa. The pressure-volume (P-V) data within 0.27-17.35 GPa were fitted to a third-order Birch-Murnaghan equation of state (BM3 EoS) to obtain the elastic coefficients including zero-pressure unit-cell volume, isothermal bulk modulus and its pressure derivative: V0 = 258.4(3) Å3, KT0 = 55(2) GPa, and K'T0 = 4.3(3). The V0 and KT0 were obtained as 258.1(2) Å3 and 57.1(6) GPa, when fixed K'T0 = 4. The axial compressional behavior of strontianite was also investigated by fitting the pressure-lattice parameter data to a parameterized form of the BM3 EoS, and the compression of the a-, b-, and c-axis was strongly anisotropic, with Ka0 = 104(6), Kb0 = 52(12), and Kc0 = 31.6(5) GPa. Based on this and previous studies using different pressure transmitting media (PTM), the effects PTM on the compressional behavior of strontianite were discussed.

PHASE TRANSITION IN LAYERED PEROVSKITE LIKE MANGANATE Ca3Mn2O7 UNDER HIGH PRESSURE

2001 ◽  
Vol 15 (18) ◽  
pp. 2491-2497 ◽  
Author(s):  
J. L. ZHU ◽  
L. C. CHEN ◽  
R. C. YU ◽  
F. Y. LI ◽  
J. LIU ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Diamond Anvil Cell ◽  
The Other ◽  
Layered Perovskite ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
Diamond Anvil

In situ high pressure energy dispersive X-ray diffraction measurements on layered perovskite-like manganate Ca 3 Mn 2 O 7 under pressures up to 35 GPa have been performed by using diamond anvil cell with synchrotron radiation. The results show that the structure of layered perovskite-like manganate Ca 3 Mn 2 O 7 is unstable under pressure due to the easy compression of NaCl-type blocks. The structure of Ca 3 Mn 2 O 7 underwent two phase transitions under pressures in the range of 0~35 GPa. One was at about 1.3 GPa with the crystal structure changing from tetragonal to orthorhombic. The other was at about 9.5 GPa with the crystal structure changing from orthorhombic back to another tetragonal.

scholarly journals In-situhigh-pressure powder X-ray diffraction study of α-zirconium phosphate

2014 ◽  
Vol 70 (3) ◽  
pp. 510-516
Author(s):  
Jennifer E. Readman ◽  
Alistair Lennie ◽  
Joseph A. Hriljac
Keyword(s):  
High Pressure ◽  
Synchrotron Radiation ◽  
Zirconium Phosphate ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
X Ray ◽  
Additional Water ◽  
Diffraction Patterns ◽  
Layered Phosphate

The high-pressure structural chemistry of α-zirconium phosphate, α-Zr(HPO4)2·H2O, was studied usingin-situhigh-pressure diffraction and synchrotron radiation. The layered phosphate was studied under both hydrostatic and non-hydrostatic conditions and Rietveld refinement carried out on the resulting diffraction patterns. It was found that under hydrostatic conditions no uptake of additional water molecules from the pressure-transmitting medium occurred, contrary to what had previously been observed with some zeolite materials and a layered titanium phosphate. Under hydrostatic conditions the sample remained crystalline up to 10 GPa, but under non-hydrostatic conditions the sample amorphized between 7.3 and 9.5 GPa. The calculated bulk modulus,K0= 15.2 GPa, showed the material to be very compressible with the weak linkages in the structure of the type Zr—O—P.

An easy to use X-ray collimator for Mao-Bell type diamond anvil cell

2006 ◽  
Vol 21 (4) ◽  
pp. 320-322 ◽  
Author(s):  
P. Ch. Sahu ◽  
N. R. Sanjay Kumar ◽  
N. V. Chandra Shekar ◽  
N. Subramanian
Keyword(s):  
High Pressure ◽  
Diamond Anvil Cell ◽  
Radiation Safety ◽  
Incident Beam ◽  
X Ray Diffraction ◽  
X Ray ◽  
Safety Requirements ◽  
Diamond Anvil ◽  
Special Precaution

An incident beam X-ray collimator for Mao-Bell type diamond anvil cell (DAC) has been developed. Alignment of the collimator is carried out in situ while viewing the image of the collimated X-ray spot formed on a thin layer of fluorescent material spread on the diamond anvil culets with the help of a microscope. Special precaution has been taken to meet the radiation safety requirements during alignment and routine use. This collimator is of immense help for laboratory based high pressure X-ray diffraction experiments.

scholarly journals High Pressure Behavior of Mascagnite from Single Crystal Synchrotron X-ray Diffraction Data

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 976
Author(s):  
Paola Comodi ◽  
Maximiliano Fastelli ◽  
Giacomo Criniti ◽  
Konstantin Glazyrin ◽  
Azzurra Zucchini
Keyword(s):  
High Pressure ◽  
Single Crystal ◽  
Room Temperature ◽  
Diamond Anvil Cell ◽  
Geometrical Parameters ◽  
X Ray Diffraction ◽  
Third Order ◽  
X Ray ◽  
Diamond Anvil ◽  
Murnaghan Equation

High-pressure synchrotron X-ray diffraction was carried out on a single crystal of mascagnite, compressed in a diamond anvil cell. The sample maintained its crystal structure up to ~18 GPa. The volume–pressure data were fitted by a third-order Birch–Murnaghan equation of state (BM3-EOS) yielding K0 = 20.4(7) GPa, K’0 = 6.1(2), and V0 = 499(1) Å3, as suggested by the F-f plot. The axial compressibilities, calculated with BM3-EOS, were K0a = 35(3), K’0a = 7.7(7), K0b = 10(3), K’0b = 7(1), K0c = 25(1), and K’0c = 4.3(2) The axial moduli measured using a BM2-EOS and fixing K’0 equal to 4, were K0a = 52(2), K0b = 20 (1), and K0c = 29.6(4) GPa, and the anisotropic ratio of K0a:K0b:K0c = 1:0.4:0.5. The evolution of crystal lattice and geometrical parameters indicated no phase transition until 17.6 GPa. Sulphate polyhedra were incompressible and the density increase of 30% compared to investigated pressure should be attributed to the reduction of weaker hydrogen bonds. In contrast, some of them, directed along [100], were very short at room temperature, below 2 Å, and showed a very low compressibility. This configuration explains the anisotropic compressional behavior and the lowest compressibility of the a axis.

scholarly journals LiCrO2 Under Pressure: In-Situ Structural and Vibrational Studies

Crystals ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 2 ◽  
Author(s):  
Alka Garg ◽  
Daniel Errandonea ◽  
Julio Pellicer-Porres ◽  
Domingo Martinez-Garcia ◽  
Swayam Kesari ◽  
...  
Keyword(s):  
Research Work ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pressure Coefficients ◽  
Vibrational Studies ◽  
Diffraction Patterns ◽  
The Stability ◽  
Murnaghan Equation ◽  
Related Compounds

The high-pressure behaviour of LiCrO2, a compound isostructural to the battery compound LiCoO2, has been investigated by synchrotron-based angle-dispersive X-ray powder diffraction, Raman spectroscopy, and resistance measurements up to 41, 30, and 10 Gpa, respectively. The stability of the layered structured compound on a triangular lattice with R-3m space group is confirmed in all three measurements up to the highest pressure reached. The dependence of lattice parameters and unit-cell volume with pressure has been determined from the structural refinements of X-ray diffraction patterns that are used to extract the axial compressibilities and bulk modulus by means of Birch–Murnaghan equation-of-state fits. The pressure coefficients for the two Raman-active modes, A1g and Eg, and their mode-Grüneisen parameters are reported. The electrical resistance measurements indicate that pressure has little influence in the resistivity up to 10 GPa. The obtained results for the vibrational and structural properties of LiCrO2 under pressure are in line with the published results of the similar studies on the related compounds. Research work reported in this article contributes significantly to enhance the understanding on the structural and mechanical properties of LiCrO2 and related lithium compounds.

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