The thermal equation of state of (Fe0.86Mg0.07Mn0.07)3Al2Si3O12 almandine

In situ X-raydiffraction measurements on almandine, (Fe0.86Mg0.07Mn0.07)3Al2Si3O12, were performed using a heating diamond-anvil cell instrument with synchrotron radiation at Beijing Synchrotron Radiation Facilityup to 27.7 GPa and 533 K. The pressure-volume-temperature data were fitted to a third-order Birch-Murnaghan equation of state. The isothermal bulk modulus of K0 = 177±2 GPa, a temperature derivative of the bulk modulus of (∂K/∂T)P= –0.032±0.016 GPaK–1 and a thermal expansion coefficient (α0) of (3.1±0.7)×10–5 K–1 were obtained. This is the first time that the temperature derivative of the bulk modulus of almandine has been determined at high pressure and high temperature. Combining these results with previous results, the compositional dependence of the bulk modulus, thermal expansion, and temperature derivative of the bulk modulus are discussed.

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Structural Study of δ-AlOOH Up to 29 GPa

Minerals ◽

10.3390/min10121055 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1055

Author(s):

Dariia Simonova ◽

Elena Bykova ◽

Maxim Bykov ◽

Takaaki Kawazoe ◽

Arkadiy Simonov ◽

...

Keyword(s):

Phase Transition ◽

Synchrotron Radiation ◽

Equation Of State ◽

Room Temperature ◽

Diamond Anvil Cell ◽

Volume Data ◽

X Ray Diffraction ◽

X Ray ◽

Diamond Anvil ◽

Murnaghan Equation

A structure and equation of the state of δ-AlOOH has been studied at room temperature, up to 29.35 GPa, by means of single crystal X-ray diffraction in a diamond anvil cell using synchrotron radiation. Above ~10 GPa, we observed a phase transition with symmetry changes from P21nm to Pnnm. Pressure-volume data were fitted with the second order Birch-Murnaghan equation of state and showed that, at the phase transition, the bulk modulus (K0) of the calculated wrt 0 pressure increases from 142(5) to 216(5) GPa.

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P–V–T Equation of State of Iridium Up to 80 GPa and 3100 K

Crystals ◽

10.3390/cryst11040452 ◽

2021 ◽

Vol 11 (4) ◽

pp. 452

Author(s):

Simone Anzellini ◽

Leonid Burakovsky ◽

Robin Turnbull ◽

Enrico Bandiello ◽

Daniel Errandonea

Keyword(s):

Thermal Expansion ◽

Equation Of State ◽

Density Functional ◽

Ambient Pressure ◽

Density Functional Theory Calculations ◽

The State ◽

Thermal Equation ◽

High Pressure High Temperature ◽

Diamond Anvil ◽

Expansion Model

In the present study, the high-pressure high-temperature equation of the state of iridium has been determined through a combination of in situ synchrotron X-ray diffraction experiments using laser-heating diamond-anvil cells (up to 48 GPa and 3100 K) and density-functional theory calculations (up to 80 GPa and 3000 K). The melting temperature of iridium at 40 GPa was also determined experimentally as being 4260 (200) K. The results obtained with the two different methods are fully consistent and agree with previous thermal expansion studies performed at ambient pressure. The resulting thermal equation of state can be described using a third-order Birch–Murnaghan formalism with a Berman thermal-expansion model. The present equation of the state of iridium can be used as a reliable primary pressure standard for static experiments up to 80 GPa and 3100 K. A comparison with gold, copper, platinum, niobium, rhenium, tantalum, and osmium is also presented. On top of that, the radial-distribution function of liquid iridium has been determined from experiments and calculations.

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Thermal equation of state of Molybdenum determined from in situ synchrotron X-ray diffraction with laser-heated diamond anvil cells

Scientific Reports ◽

10.1038/srep19923 ◽

2016 ◽

Vol 6 (1) ◽

Cited By ~ 15

Author(s):

Xiaoli Huang ◽

Fangfei Li ◽

Qiang Zhou ◽

Yue Meng ◽

Konstantin D. Litasov ◽

...

Keyword(s):

Equation Of State ◽

X Ray Diffraction ◽

Diamond Anvil Cells ◽

Thermal Equation ◽

X Ray ◽

Thermal Equation Of State ◽

Diamond Anvil ◽

Laser Heated

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Synthesis and Compressibility of Novel Nickel Carbide at Pressures of Earth’s Outer Core

Minerals ◽

10.3390/min11050516 ◽

2021 ◽

Vol 11 (5) ◽

pp. 516

Author(s):

Timofey Fedotenko ◽

Saiana Khandarkhaeva ◽

Leonid Dubrovinsky ◽

Konstantin Glazyrin ◽

Pavel Sedmak ◽

...

Keyword(s):

Equation Of State ◽

Outer Core ◽

Direct Reaction ◽

Volume Data ◽

X Ray Diffraction ◽

Nickel Carbide ◽

Diamond Anvils ◽

Group A ◽

Diamond Anvil ◽

Murnaghan Equation

We report the high-pressure synthesis and the equation of state (EOS) of a novel nickel carbide (Ni3C). It was synthesized in a diamond anvil cell at 184(5) GPa through a direct reaction of a nickel powder with carbon from the diamond anvils upon heating at 3500 (200) K. Ni3C has the cementite-type structure (Pnma space group, a = 4.519(2) Å, b = 5.801(2) Å, c = 4.009(3) Å), which was solved and refined based on in-situ synchrotron single-crystal X-ray diffraction. The pressure-volume data of Ni3C was obtained on decompression at room temperature and fitted to the 3rd order Burch-Murnaghan equation of state with the following parameters: V0 = 147.7(8) Å3, K0 = 157(10) GPa, and K0' = 7.8(6). Our results contribute to the understanding of the phase composition and properties of Earth’s outer core.

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A combined study of the equation of state of monazite-type lanthanum orthovanadate usingin situhigh-pressure diffraction andab initiocalculations

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials ◽

10.1107/s2052520614010816 ◽

2014 ◽

Vol 70 (3) ◽

pp. 533-538 ◽

Cited By ~ 10

Author(s):

Olga Ermakova ◽

Javier López-Solano ◽

Roman Minikayev ◽

Stefan Carlson ◽

Agata Kamińska ◽

...

Keyword(s):

Equation Of State ◽

Density Functional ◽

Room Temperature ◽

Theoretical Data ◽

Perfect Agreement ◽

Functional Theory ◽

Compression Direction ◽

The Density Functional Theory ◽

Murnaghan Equation

Lanthanum orthovanadate (LaVO4) is the only stable monazite-type rare-earth orthovanadate. In the present paper the equation of state of LaVO4is studied usingin situhigh-pressure powder diffraction at room temperature, andab initiocalculations within the framework of the density functional theory. The parameters of a second-order Birch–Murnaghan equation of state,i.e.those fitted to the experimental and theoretical data, are found to be in perfect agreement – in particular, the bulk moduli are almost identical, with values of 106 (1) and 105.8 (5) GPa, respectively. In agreement with recent reported experimental data, the compression is shown to be anisotropic. Its nature is comparable to that of some other monazite-type compounds. The softest compression direction is determined.

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P–V–T equation of state of molybdenite (MoS2) by a diamond anvil cell and in situ synchrotron angle-dispersive X-ray diffraction

Physica B Condensed Matter ◽

10.1016/j.physb.2014.06.023 ◽

2014 ◽

Vol 451 ◽

pp. 53-57 ◽

Cited By ~ 6

Author(s):

Dawei Fan ◽

Jingui Xu ◽

Maining Ma ◽

Jing Liu ◽

Hongsen Xie

Keyword(s):

Equation Of State ◽

Diamond Anvil Cell ◽

X Ray Diffraction ◽

X Ray ◽

Diamond Anvil

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The deformation mechanism of a pressure-induced phase transition in dehydrated analcime

Mineralogical Magazine ◽

10.1180/minmag.2012.076.1.129 ◽

2012 ◽

Vol 76 (1) ◽

pp. 129-142 ◽

Cited By ~ 6

Author(s):

A. Yu. Likhacheva ◽

S. V. Rashchenko ◽

Yu. V. Seryotkin

Keyword(s):

Phase Transition ◽

Equation Of State ◽

Structure Type ◽

Elastic Behaviour ◽

Structural Behaviour ◽

Synchrotron Powder Diffraction ◽

First Order Phase Transition ◽

Diamond Anvil ◽

First Order Phase ◽

Murnaghan Equation

AbstractThe elastic and structural behaviour of dehydrated analcime in compression in a non-penetrating medium up to 3 GPa was studied in a diamond anvil cell using in situ synchrotron powder diffraction. A first-order phase transition at 0.4–0.7 GPa is accompanied by a symmetry change from monoclinic (I2/a) to pseudo-rhombohedral (R3) due to trigonalization of the aluminosilicate framework. This is due to the migration of cations to new positions close to the 6-membered rings forming the channels. The reduction of the mean aperture of the structure-forming 6- and 8-membered rings, as a result of tetrahedral tilting, leads to a 7.5% reduction in volume at the phase transition. The bulk modulus values are 38(2) GPa for the low pressure (LP) phase [fitted with a Murnaghan equation of state, K' = 4 (fixed)] and 11(4) GPa for the high pressure (HP) phase [fitted with a third-order Birch–Murnaghan equation of state, K' = 9(1)]. The elastic behaviour of the LP phase is anisotropic, with compressibilities βa:βb:βc in the ratio 1:4:2; the most compressible direction b coinciding with the orientation of empty 8-membered rings. The compressibility of the HP phase is isotropic. Trigonalization appears to be the most effective (and probably unique) mechanism of radical volume contraction for the ANA structure type.

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Thermodynamic Properties of La1-xSmxCoO3

International Journal of Metals ◽

10.1155/2014/616525 ◽

2014 ◽

Vol 2014 ◽

pp. 1-5

Author(s):

Rasna Thakur ◽

N. K. Gaur

Keyword(s):

Experimental Data ◽

Thermal Expansion ◽

Thermal Properties ◽

Bulk Modulus ◽

Specific Heat ◽

Specific Heats ◽

Lattice Specific Heat ◽

Lattice Distortions ◽

First Time ◽

Rigid Ion Model

We have investigated the bulk modulus and thermal properties of La1-xSmxCoO3 (0≤x≤0.2) at temperatures 1 K≤T≤300 K probably for the first time by incorporating the effect of lattice distortions using the modified rigid ion model (MRIM). The calculated specific heat, thermal expansion, bulk modulus, and other thermal properties reproduce well with the available experimental data, implying that MRIM represents properly the nature of the pure and doped cobaltate. The specific heats are found to increase with temperature and decrease with concentration (x) for the present. The increase in Debye temperature (θD) indicates an anomalous softening of the lattice specific heat because increase in T3-term in the specific heat occurs with the decrease of concentration (x).

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