scholarly journals Grüneisen parameter and high temperature and high pressure equation of state for aluminum

2009 ◽  
Vol 58 (3) ◽  
pp. 1879
Author(s):  
Song Ping ◽  
Cai Ling-Cang
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Equation Of State ◽  
Grüneisen Parameter ◽  
Pressure Equation ◽  
Gruneisen Parameter

High-temperature and high-pressure equation of state for the hexagonal phase in the system NaAlSiO4 – MgAl2O4

2005 ◽  
Vol 32 (8-9) ◽  
pp. 594-602 ◽  
Author(s):  
T. Shinmei ◽  
T. Sanehira ◽  
D. Yamazaki ◽  
T. Inoue ◽  
T. Irifune ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Equation Of State ◽  
Hexagonal Phase ◽  
Pressure Equation

Thermoelastic properties and crystal structure of CaPtO3post-perovskite from 0 to 9 GPa and from 2 to 973 K

2011 ◽  
Vol 44 (5) ◽  
pp. 999-1016 ◽  
Author(s):  
Alex Lindsay-Scott ◽  
Ian G. Wood ◽  
David P. Dobson ◽  
Lidunka Vočadlo ◽  
John P. Brodholt ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Equation Of State ◽  
Powder Diffraction ◽  
Ambient Pressure ◽  
Full Range ◽  
Unit Cell ◽  
Similar Amount ◽  
Grüneisen Parameter ◽  
Gruneisen Parameter

ABX3post-perovskite (PPV) phases that are stable (or strongly metastable) at ambient pressure are important as analogues of PPV-MgSiO3, a deep-Earth phase stable only at very high pressure. The thermoelastic and structural properties of orthorhombic PPV-structured CaPtO3have been determined to 9.27 GPa at ambient temperature and from 2 to 973 K at ambient pressure by time-of-flight neutron powder diffraction. The equation-of-state from this high-pressure study is consistent with that found by Lindsay-Scott, Wood, Dobson, Vočadlo, Brodholt, Crichton, Hanfland & Taniguchi [(2010).Phys. Earth Planet. Inter.182, 113–118] using X-ray powder diffraction to 40 GPa. However, the neutron data have also enabled the determination of the crystal structure. Thebaxis is the most compressible and thecaxis the least, with theaandcaxes shortening under pressure by a similar amount. Above 300 K, the volumetric coefficient of thermal expansion, α(T), of CaPtO3can be represented by α(T) =a0+a1(T), witha0= 2.37 (3) × 10−5 K−1anda1= 5.1 (5) × 10−9 K−2. Over the full range of temperature investigated, the unit-cell volume of CaPtO3can be described by a second-order Grüneisen approximation to the zero-pressure equation of state, with the internal energy calculatedviaa Debye model and parameters θD(Debye temperature) = 615 (8) K,V0(unit-cell colume at 0 K) = 227.186 (3) Å3,K′0(first derivative with respect to pressure of the isothermal incompressibilityK0) = 7.9 (8) and (V0K0/γ′) = 3.16 (3) × 10−17 J, where γ′ is a Grüneisen parameter. Combining the present measurements with heat-capacity data gives a thermodynamic Grüneisen parameter γ = 1.16 (1) at 291 K. PPV-CaPtO3, PPV-MgSiO3and PPV-CaIrO3have the same axial incompressibility sequence, κc > κa > κb. However, when heated, CaPtO3shows axial expansion in the form αc > αb > αa, a sequence which is not simply the inverse of the axial incompressibilities. In this respect, CaPtO3differs from both MgSiO3(where the sequence αb > αa > αcis the same as 1/κi) and CaIrO3(where αb > αc > αa). Thus, PPV-CaPtO3and PPV-CaIrO3are better analogues for PPV-MgSiO3in compression than on heating. The behaviour of the unit-cell axes of all three compounds was analysed using a model based on nearest-neighbourB—XandA—Xdistances and angles specifying the geometry and orientation of theBX6octahedra. Under pressure, all contract mainly by reduction in theB—XandA—Xdistances. On heating, MgSiO3expands (at high pressure) mainly by lengthening of the Si—O and Mg—O bonds. In contrast, the expansion of CaPtO3(and possibly also CaIrO3), at atmospheric pressure, arises more from changes in angles than from increased bond distances.

Equation of state and phase transition of antigorite under high pressure and high temperature

2014 ◽  
Vol 228 ◽  
pp. 56-62 ◽  
Author(s):  
Cuiping Yang ◽  
Toru Inoue ◽  
Akihiro Yamada ◽  
Takumi Kikegawa ◽  
Jun-ichi Ando
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
High Temperature ◽  
Equation Of State
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