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1.
Xi Liu Michael E. Fleet Sean R. Shieh Qiang He 《Physics and Chemistry of Minerals》2011,38(5):397-406
Lead bromapatite [Pb10(PO4)6Br2] has been synthesized via solid-state reaction at pressures up to 1.0 GPa, and its structure determined by single-crystal
X-ray diffraction at ambient temperature and pressure. The large bromide anion is accommodated in the c-axis channel by lateral displacements of structural elements, particularly of Pb2 cations and PO4 tetrahedra. The compressibility of bromapatite was also investigated up to about 20.7 GPa at ambient temperature, using a
diamond-anvil cell and synchrotron X-ray radiation. The compressibility of lead bromapatite is significantly different from
that of lead fluorapatite. The pressure–volume data of lead bromapatite (P < 10 GPa) fitted to the third-order Birch-Murnaghan equation yield an isothermal bulk modulus (K
T
) of 49.8(16) GPa and first pressure derivative (KT¢ K_{T}^{\prime } ) of 10.1(10). If KT¢ K_{T}^{\prime } is fixed at 4, the derived K
T
is 60.8(11) GPa. The relative difference of the bulk moduli of these two lead apatites is thus about 12%, which is about
two times the relative difference of the bulk moduli (~5%) of the calcium apatites fluorapatite [Ca10(PO4)6F2], chlorapatite [Ca10(PO4)6Cl2] and hydroxylapatite [Ca10(PO4)6(OH)2]. Another interesting feature apparently related to the replacement of F by Br in lead apatite is the switch in the principle
axes of the strain ellipsoid: the c-axis is less compressible than the a-axis in lead bromapatite but more compressible in lead fluorapatite. 相似文献
2.
Qiang He Xi Liu Xiaomin Hu Sicheng Li Hejing Wang 《Physics and Chemistry of Minerals》2011,38(10):741-752
The solid solution between lead fluorapatite and lead fluorvanadate apatite, Pb10[(PO4)6-x
(VO4)
x
]F2 with x equal to 0, 1, 2, 3, 4, 5 and 6, was synthesized by solid-state reaction at 1 atm and 700°C for 72 h and characterized by
scanning electronic microprobe, electronic microprobe analysis, micro-Raman spectroscopy, and powder X-ray diffraction. The
volume-composition relationship at ambient temperature does not show significant deviation from the Vegard’s Law. The Raman
spectrum data suggest that both P and V are identical on a C
s
site and both end-members show no apparent factor-group effect. The Raman frequency shift of the symmetric stretching vibration
is linearly dependent on the composition. High temperature X-ray diffraction data, up to 600°C, suggest that the thermal expansion
coefficients α
a
, α
c
, and α
V
also vary linearly with the compositions of the apatites. 相似文献
3.
Behavior of epidote at high pressure and high temperature: a powder diffraction study up to 10 GPa and 1,200 K 总被引:1,自引:0,他引:1
G. Diego Gatta Marco Merlini Yongjae Lee Stefano Poli 《Physics and Chemistry of Minerals》2011,38(6):419-428
The thermo-elastic behavior of a natural epidote [Ca1.925 Fe0.745Al2.265Ti0.004Si3.037O12(OH)] has been investigated up to 1,200 K (at 0.0001 GPa) and 10 GPa (at 298 K) by means of in situ synchrotron powder diffraction.
No phase transition has been observed within the temperature and pressure range investigated. P–V data fitted with a third-order Birch–Murnaghan equation of state (BM-EoS) give V
0 = 458.8(1)Å3, K
T0 = 111(3) GPa, and K′ = 7.6(7). The confidence ellipse from the variance–covariance matrix of K
T0 and K′ from the least-square procedure is strongly elongated with negative slope. The evolution of the “Eulerian finite strain”
vs “normalized stress” yields Fe(0) = 114(1) GPa as intercept values, and the slope of the regression line gives K′ = 7.0(4). The evolution of the lattice parameters with pressure is slightly anisotropic. The elastic parameters calculated
with a linearized BM-EoS are: a
0 = 8.8877(7) Å, K
T0(a) = 117(2) GPa, and K′(a) = 3.7(4) for the a-axis; b
0 = 5.6271(7) Å, K
T0(b) = 126(3) GPa, and K′(b) = 12(1) for the b-axis; and c
0 = 10.1527(7) Å, K
T0(c) = 90(1) GPa, and K’(c) = 8.1(4) for the c-axis [K
T0(a):K
T0(b):K
T0(c) = 1.30:1.40:1]. The β angle decreases with pressure, βP(°) = βP0 −0.0286(9)P +0.00134(9)P
2 (P in GPa). The evolution of axial and volume thermal expansion coefficient, α, with T was described by the polynomial function: α(T) = α0 + α1
T
−1/2. The refined parameters for epidote are: α0 = 5.1(2) × 10−5 K−1 and α1 = −5.1(6) × 10−4 K1/2 for the unit-cell volume, α0(a) = 1.21(7) × 10−5 K−1 and α1(a) = −1.2(2) × 10−4 K1/2 for the a-axis, α0(b) = 1.88(7) × 10−5 K−1 and α1(b) = −1.7(2) × 10−4 K1/2 for the b-axis, and α0(c) = 2.14(9) × 10−5 K−1 and α1(c) = −2.0(2) × 10−4 K1/2 for the c-axis. The thermo-elastic anisotropy can be described, at a first approximation, by α0(a): α0(b): α0(c) = 1 : 1.55 : 1.77. The β angle increases continuously with T, with βT(°) = βT0 + 2.5(1) × 10−4
T + 1.3(7) × 10−8
T
2. A comparison between the thermo-elastic parameters of epidote and clinozoisite is carried out. 相似文献
4.
The structure of lead fluorapatite [PbFAP; Pb10(PO4)6F2], crystallized from the melt in a platinum capsule at 1,000°C and 1 atm, has been investigated by single-crystal X-ray diffraction. Crystal data are a = 9.7638 (6), c = 7.2866 (4) Å, space group P63/m, R = 0.043, R w = 0.034. We have also studied the compressional behaviour of the c-axis channel of PbFAP up to 9 GPa at 25°C, using a diamond-anvil cell, synchrotron X-radiation, and Rietveld powder structure refinement. Pressure–volume data for the channel polyhedron of PbFAP fitted to the third-order Birch–Murnaghan equation resulted in K T = 33.2 ± 1.2 GPa when K T ′ is fixed at 4. The c-axis channel of PbFAP is about twice as compressible as the unit-cell volume of PbFAP and the channel of calcium apatites. This is attributed to the anomalous narrowing of the channel of PbFAP with increase in confining pressure. Flexibility of the apatite channel is a key factor in the scavenging of toxic heavy metals by calcium apatites. 相似文献
5.
Carine B. Vanpeteghem Ross J. Angel Jing Zhao Nancy L. Ross Günther J. Redhammer Friedrich Seifert 《Physics and Chemistry of Minerals》2008,35(9):493-504
The structural evolution with pressure and the equations of state of three members of the brownmillerite solid solution, Ca2(Fe2−x
Al
x
)O5, have been determined by single-crystal X-ray diffraction up to a maximum pressure of 9.73 GPa. The compositions of the samples
were x = 0.00 and x = 0.37 (with Pnma symmetry) and x = 0.55 (with I2mb symmetry). No phase transitions were observed in the experiments. The equation of state parameters determined from the pressure-volume
data are K
0T = 128.0 (7) GPa, K′0 = 5.8 (3) for the sample with x = 0.00, K
0T = 131 (2) GPa, K′0 = 5.5 (4) for x = 0.37, and K
0T = 137.5 (6) GPa, K′0 = 4 for x = 0.55. The bulk modulus therefore increases with Al content, being 11% higher in the x = 0.55 sample than in the Al-free sample. The unit-cell compression is anisotropic, with the c-axis being stiffer than a or b, and the anisotropy increases with increasing Al content of the structure. The structural response to pressure of all samples
is similar. The (Al,Fe)O4 tetrahedra and the (Al,Fe)O6 octahedra undergo approximately isotropic compression. There is an increase in the twists of the chains of corner-sharing
(Al,Fe)O4 tetrahedra, and an increase in the tilts of the (Al,Fe)O6 octahedra, because these framework polyhedra are stiffer than the Ca–O bonds to the extra-framework Ca site. The alignment
of the two shortest Ca–O bonds sub-parallel to [001] accounts for the relative stiffness of the c-axis and thus the elastic anisotropy.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
6.
G. Diego Gatta Marco Merlini Hanns-Peter Liermann André Rothkirch Mauro Gemmi Alessandro Pavese 《Physics and Chemistry of Minerals》2012,39(5):385-397
The thermoelastic behavior of a natural clintonite-1M [with composition: Ca1.01(Mg2.29Al0.59Fe0.12)Σ3.00(Si1.20Al2.80)Σ4.00O10(OH)2] has been investigated up to 10 GPa (at room temperature) and up to 960°C (at room pressure) by means of in situ synchrotron
single-crystal and powder diffraction, respectively. No evidence of phase transition has been observed within the pressure
and temperature range investigated. P–V data fitted with an isothermal third-order Birch–Murnaghan equation of state (BM-EoS) give V
0 = 457.1(2) ?3, K
T0 = 76(3)GPa, and K′ = 10.6(15). The evolution of the “Eulerian finite strain” versus “normalized stress” shows a linear positive trend. The
linear regression yields Fe(0) = 76(3) GPa as intercept value, and the slope of the regression line leads to a K′ value of 10.6(8). The evolution of the lattice parameters with pressure is significantly anisotropic [β(a) = 1/3K
T0(a) = 0.0023(1) GPa−1; β(b) = 1/3K
T0(b) = 0.0018(1) GPa−1; β(c) = 1/K
T0(c) = 0.0072(3) GPa−1]. The β-angle increases in response to the applied P, with: βP = β0 + 0.033(4)P (P in GPa). The structure refinements of clintonite up to 10.1 GPa show that, under hydrostatic pressure, the structure rearranges
by compressing mainly isotropically the inter-layer Ca-polyhedron. The bulk modulus of the Ca-polyhedron, described using
a second-order BM-EoS, is K
T0(Ca-polyhedron) = 41(2) GPa. The compression of the bond distances between calcium and the basal oxygens of the tetrahedral
sheet leads, in turn, to an increase in the ditrigonal distortion of the tetrahedral ring, with ∂α/∂P ≈ 0.1°/GPa within the P-range investigated. The Mg-rich octahedra appear to compress in response to the applied pressure, whereas the tetrahedron
appears to behave as a rigid unit. The evolution of axial and volume thermal expansion coefficient α with temperature was
described by the polynomial α(T) = α0 + α1
T
−1/2. The refined parameters for clintonite are as follows: α0 = 2.78(4) 10−5°C−1 and α1 = −4.4(6) 10−5°C1/2 for the unit-cell volume; α0(a) = 1.01(2) 10−5°C−1 and α1(a) = −1.8(3) 10−5°C1/2 for the a-axis; α0(b) = 1.07(1) 10−5°C−1 and α1(b) = −2.3(2) 10−5°C1/2 for the b-axis; and α0(c) = 0.64(2) 10−5°C−1 and α1(c) = −7.3(30) 10−6°C1/2for the c-axis. The β-angle appears to be almost constant within the given T-range. No structure collapsing in response to the T-induced dehydroxylation was found up to 960°C. The HP- and HT-data of this study show that in clintonite, the most and the less expandable directions do not correspond to the most and
the less compressible directions, respectively. A comparison between the thermoelastic parameters of clintonite and those
of true micas was carried out. 相似文献
7.
The elastic behaviour and the high-pressure structural evolution of a natural topaz, Al2.00Si1.05O4.00(OH0.26F1.75), have been investigated by means of in situ single-crystal X-ray diffraction up to 10.55(5) GPa. No phase transition has been observed within the pressure range investigated. Unit-cell volume data were fitted with a third-order Birch-Murnaghan Equation of State (III-BM-EoS). The III-BM-EoS parameters, simultaneously refined using the data weighted by the uncertainties in P and V, are: V
0=345.57(7) Å3, K
T0=164(2) GPa and K′=2.9(4). The axial-EoS parameters are: a
0=4.6634(3) Å, K
T0(a)=152(2) GPa, K′(a)=2.8(4) for the a-axis; b
0=8.8349(5) Å, K
T0(b)=224(3) GPa, K′(b)=2.6(6) for the b-axis; c
0=8.3875(7) Å, K
T0(c)=137(2) GPa, K′(c)=2.9(4) for the c-axis. The magnitude and the orientation of the principal Lagrangian unit-strain ellipsoid were determined. At P−P
0=10.55 GPa, the ratios ε1:ε2:ε3 are 1.00:1.42:1.56 (with ε1||b, ε2||a, ε3||c and |ε3| > |ε2| > |ε1|). Four structural refinements, performed at 0.0001, 3.14(5), 5.79(5) and 8.39(5) GPa describe the structural evolution in terms of polyhedral distortions. 相似文献
8.
P. Comodi G. D. Gatta P. F. Zanazzi D. Levy W. Crichton 《Physics and Chemistry of Minerals》2002,29(8):538-544
Powder diffraction measurements at simultaneous high pressure and temperature on samples of 2M1 polytype of muscovite (Ms) and paragonite (Pg) were performed at the beamline ID30 of ESRF (Grenoble), using the Paris-Edinburgh
cell. The bulk moduli of Ms, calculated from the least-squares fitting of V–P data on each isotherm using a second-order Birch–Murnaghan EoS, were: 57.0(6), 55.1(7), 51.1(7) and 48.9(5) GPa on the isotherms
at 298, 573, 723 and 873 K, respectively. The value of (∂K
T
/∂T)
was −0.0146(2) GPa K−1. The thermal expansion coefficient α varied from 35.7(3) × 10−6 K−1 at P ambient to 20.1(3) × 10−6 K−1 at P = 4 GPa [(∂α/∂P)
T
= −3.9(1) × 10−6 GPa−1 K−1]. The corresponding values for Pg on the isotherms at 298, 723 and 823 K were: bulk moduli 59.9(5), 55.7(6) and 53.8(7) GPa,
(∂K
T
/∂T)
−0.0109(1) GPa K−1. The thermal expansion coefficient α varied from 44.1(2) × 10−6 K−1 at P ambient to 32.5(2) × 10−6 K−1 at P = 4 GPa [(∂α/∂P)
T
= −2.9(1) × 10−6 GPa−1 K−1]. Thermoelastic coefficients showed that Pg is stiffer than Ms; Ms softens more rapidly than Pg upon heating; thermal expansion
is greater and its variation with pressure is smaller in Pg than in Ms.
Received: 28 January 2002 / Accepted: 5 April 2002 相似文献
9.
The high-pressure elastic behaviour of a synthetic zeolite mordenite, Na6Al6.02Si42.02O96·19H2O [a=18.131(2), b=20.507(2), c=7.5221(5) Å, space group Cmc21], has been investigated by means of in situ synchrotron X-ray powder diffraction up to 5.68 GPa. No phase transition has been observed within the pressure range investigated. Axial and volume bulk moduli have been calculated using a truncated second-order Birch–Murnaghan equation-of-state (II-BM-EoS). The refined elastic parameters are: V
0=2801(11) Å3, K
T0= 41(2) GPa for the unit-cell volume; a
0=18.138(32) Å, K
T0(a)=70(8) GPa for the a-axis; b
0=20.517(35) Å, K
T0(b)=29(2) GPa for the b-axis and c
0=7.531(5) Å, K
T0(c)=38(1) GPa for the c-axis [K
T0(a): K
T0(b): K
T0(c)=2.41:1.00:1.31]. Axial and volume Eulerian finite strain versus “normalized stress” plots (fe–Fe plot) show an almost linear trend and the weighted linear regression through the data points yields the following intercept values: Fe(0)=39(4) GPa for V; Fe
a
(0)=65(18) GPa for a; Fe
b
(0)=28(3) GPa for b; Fe
c
(0)=38(2) GPa for c. The magnitudes of the principal Lagrangian unit-strain coefficients, between 0.47 GPa (the lowest HP-data point) and each measured P>0.47 GPa, were calculated. The unit-strain ellipsoid is oriented with ε1 || b, ε2 || c, ε3 || a and |ε1|> |ε2|> |ε3|. Between 0.47 and 5.68 GPa the relationship between the unit-strain coefficient is ε1: ε2: ε3=2.16:1.81:1.00. The reasons of the elastic anisotropy are discussed.An erratum to this article can be found at 相似文献
10.
A. Pavese V. Diella V. Pischedda M. Merli R. Bocchio M. Mezouar 《Physics and Chemistry of Minerals》2001,28(4):242-248
The thermoelastic parameters of natural andradite and grossular have been investigated by high-pressure and -temperature
synchrotron X-ray powder diffraction, at ESRF, on the ID30 beamline. The P–V–T data have been fitted by Birch-Murnaghan-like EOSs, using both the approximated and the general form. We have obtained for
andradite K
0=158.0(±1.5) GPa, (dK/dT )0=−0.020(3) GPa K−1 and α0=31.6(2) 10−6 K−1, and for grossular K
0=168.2(±1.7) GPa, (dK/dT)0=−0.016(3) GPa K−1 and α0=27.8(2) 10−6 K−1. Comparisons between the present issues and thermoelastic properties of garnets earlier determined are carried out.
Received: 7 July 2000 / Accepted: 20 October 2000 相似文献
11.
Sicheng Wang Xi Liu Yingwei Fei Qiang He Hejing Wang 《Physics and Chemistry of Minerals》2012,39(3):189-198
Using a conventional high-T furnace, the solid solutions between magnesiochromite and manganochromite, (Mg1−x
Mn
x
)Cr2O4 with x = 0.00, 0.19, 0.44, 0.61, 0.77 and 1.00, were synthesized at 1,473 K for 48 h in open air. The ambient powder X-ray diffraction
data suggest that the V–x relationship of the spinels does not show significant deviation from the Vegard’s law. In situ high-T powder X-ray diffraction measurements were taken up to 1,273 K at ambient pressure. For the investigated temperature range,
the unit-cell parameters of the spinels increase smoothly with temperature increment, indicating no sign of cation redistribution
between the tetrahedral and octahedral sites. The V–T data were fitted with a polynomial expression for the volumetric thermal expansion coefficient (aT = a0 + a1 T + a2 T - 2 \alpha_{T} = a_{0} + a_{1} T + a_{2} T^{ - 2} ), which yielded insignificant a
2 values. The effect of the composition on a
0 is adequately described by the equation a
0 = [17.7(8) − 2.4(1) × x] 10−6 K−1, whereas that on a
1 by the equation a
1 = [8.6(9) + 2.1(11) × x] 10−9 K−2. 相似文献
12.
Shuangmeng Zhai Weihong Xue Daisuke Yamazaki Shuangming Shan Eiji Ito Naotaka Tomioka Akira Shimojuku Ken-ichi Funakoshi 《Physics and Chemistry of Minerals》2011,38(5):357-361
High pressure in situ synchrotron X-ray diffraction experiment of strontium orthophosphate Sr3(PO4)2 has been carried out to 20.0 GPa at room temperature using multianvil apparatus. Fitting a third-order Birch–Murnaghan equation of state to the P–V data yields a volume of V 0 = 498.0 ± 0.1 Å3, an isothermal bulk modulus of K T = 89.5 ± 1.7 GPa, and first pressure derivative of K T ′ = 6.57 ± 0.34. If K T ′ is fixed at 4, K T is obtained as 104.4 ± 1.2 GPa. Analysis of axial compressible modulus shows that the a-axis (K a = 79.6 ± 3.2 GPa) is more compressible than the c-axis (K c = 116.4 ± 4.3 GPa). Based on the high pressure Raman spectroscopic results, the mode Grüneisen parameters are determined and the average mode Grüneisen parameter of PO4 vibrations of Sr3(PO4)2 is calculated to be 0.30(2). 相似文献
13.
D. G. Isaak J. D. Carnes O. L. Anderson H. Cynn E. Hake 《Physics and Chemistry of Minerals》1998,26(1):31-43
The ambient pressure elastic properties of single-crystal TiO2 rutile are reported from room temperature (RT) to 1800 K, extending by more than 1200 oK the maximum temperature for which rutile elasticity data are available. The magnitudes
of the temperature derivatives decrease with increasing temperature for five of the six adiabatic elastic moduli (C
ij
). At RT, we find (units, GPa): C
11=268(1); C
33=484(2); C
44=123.8(2); C
66=190.2(5); C
23=147(1); and C
12=175(1). The temperature derivatives (units, GPa K−1) at RT are: (∂C
11/∂T)
P
=−0.042(5); (∂C
33/∂T)
P
=−0.087(6); (∂C
44/∂T)
P
=−0.0187(2); (∂C
66/∂T)
P
=−0.067(2); (∂C
23/∂T)
P
=−0.025; and (∂C
12/∂T)
P
−0.048(5). The values for K
S
(adiabatic bulk modulus) and μ (isotropic shear modulus) and their temperature derivatives are K
S
=212(1) GPa; μ=113(1) GPa; (∂K
S
/∂T)
P
=−0.040(4) GPa K−1; and (∂μ/∂T)
P
=−0.018(1) GPa K−1. We calculate several dimensionless parameters over a large temperature range using our new data. The unusually high values
for the Anderson-Gròneisen parameters at room temperature decrease with increasing temperature. At high T, however, these parameters are still well above those for most other oxides. We also find that for TiO2, anharmonicity, as evidenced by a non-zero value of [∂ln (K
T
)/∂lnV]
T
, is insignificant at high T, implying that for the TiO2 analogue of stishovite, thermal pressure is independent of volume (or pressure). Systematic relations indicate that ∂2
K
S
/∂T∂P is as high as 7×10−4 K−1 for rutile, whereas ∂2μ/∂T∂P is an order of magnitude less.
Received: 19 September 1997 / Revised, accepted: 27 February 1998 相似文献
14.
Nancy L. Ross 《Physics and Chemistry of Minerals》1998,25(8):597-602
The crystal structure of orthorhombic (Pbnm) ScAlO3 perovskite has been refined to 5 GPa using single-crystal X-ray diffraction. The compression of the structure if anisotropic
with β
a
=1.39(3)×10−3 GPa−1, β
b
=1.14(3)×10−3 GPa−1 and β
c
=1.84(3)×10−3 GPa−1. The isothermal bulk modulus of ScAlO3, K
T
, determined from fitting a Birch-Murnaghan equation of state (K
′
T
=4) to the volume compression data is 218(1) GPa. The interoctahedral angles to not vary significantly with pressure, and
the compression of the structure is entirely attributable to compression of the AlO6 octahedra. The compressibilities of the constituent AlO6 and ScO12 are well matched: βAl−O=1.6×10−3 GPa−1 and βSc−O=1.5×10−3 GPa−1. Therefore the distortion of the structure shows no significant change with increasing pressure.
Received: 18 August 1997 / Revised, accepted: 11 November 1997 相似文献
15.
Sytle M. Antao Ian Jackson Baosheng Li Jennifer Kung Jiuhua Chen Ishmael Hassan Robert C. Liebermann John B. Parise 《Physics and Chemistry of Minerals》2007,34(5):345-350
The elastic moduli of magnesioferrite spinel, MgFe2O4, and their temperature dependence have been determined for the first time by ultrasonic measurements on a polycrystalline
specimen. The measurements were carried out at 300 MPa and to 700°C in a gas-medium high-pressure apparatus. On heating, both
the elastic bulk (K
S) and shear (G) moduli decrease linearly to 350°C. By combining with extant thermal-expansion data, the values for the room-temperature
K
S and G, and their temperature derivatives are as follows: K
0 = 176.3(7) GPa, G
0 = 80.1(2) GPa, (∂K
S/∂T)
P
= −0.032(3) GPa K−1 and (∂G/∂T)
P
= −0.012(1) GPa K−1. Between 350 and 400°C, there are abrupt increases of 1.4% in both of the elastic moduli; these closely coincide with the
magnetic Curie transition that was observed by thermal analyses at about 360°C. 相似文献
16.
Norimasa Nishiyama Takehiko Yagi Shigeaki Ono Hirotada Gotou Tatsuhiko Harada Takumi Kikegawa 《Physics and Chemistry of Minerals》2007,34(3):131-143
In situ X-ray diffraction measurements of Fe- and Al-bearing MgSiO3-rich perovskite (FeAl-Pv), which was synthesized from a natural orthopyroxene, were performed at pressures of 19–32 GPa and
temperatures of 300–1,500 K using a combination of a Kawai-type apparatus with eight sintered-diamond anvils and synchrotron
radiation. Two runs were performed using a high-pressure cell with two sample chambers, and both MgSiO3 perovskite (Mg-Pv) and FeAl-Pv were synthesized simultaneously in the same cell. Thus we were able to measure specific volumes
(V/V
0) of Mg-Pv and FeAl-Pv at the same P−T conditions. At all the measurement conditions, values of the specific volume of FeAl-Pv are consistent with those of Mg-Pv
within 2 Standard Deviation, strongly suggesting that effect of incorporation of iron and aluminum on the thermoelastic properties
of magnesium silicate perovskite is undetectable in this composition, pressure, and temperature range. Two additional runs
were performed using a high-pressure cell that has one sample chamber and unit-cell volumes of FeAl-Pv were measured at pressures
and temperatures up to 32 GPa and 1,500 K, respectively. All the unit-cell volume data of FeAl-Pv perovskite were fitted to
the high temperature Birch–Murnaghan equation of state and a complete set of thermoelastic parameters of this perovskite was
determined with an assumption of K′
300,0 = 4. The determined parameters are K
300,0 = 243(3) GPa, (∂K
T,0/∂T)
P
= −0.030(8) GPa/K, a
0 = 2.78(18) × 10−5 K−1, and b
0 = 0.88(28) × 10−8 K−2, where a
0 and b
0 are the coefficients of the following expression describing the zero-pressure thermal expansion: α
T,0 = a
0 + b
0
T. The equation-of-state parameters of FeAl-Pv are in good agreement with those of MgSiO3 perovskite at the conditions corresponding to the uppermost part of the lower mantle. 相似文献
17.
Takahiro Kuribayashi Masahiko Tanaka Yasuhiro Kudoh 《Physics and Chemistry of Minerals》2008,35(10):559-568
The natural norbergite, Mg2.98Fe0.01Ti0.02Si0.99O4(OH0.31F1.69) is examined by synchrotron X-ray diffraction analysis at pressures up to 8.2 GPa. The measured linear compressibilities
of the crystallographic axes are β
a
= 2.18(4) × 10−3, β
b
= 2.93(7) × 10−3, and β
c
= 2.77(7) × 10−3 (GPa−1), respectively and the calculated isothermal bulk modulus of the norbergite is K
T = 113(2) GPa based on the Birch–Murnaghan equation of state assuming a pressure derivative of K′ = 4. The crystal structures of norbergite are refined at room temperature and pressures of 4.7, 6.3, and 8.2 GPa, yielding
R values for the structure refinements of 4.6, 5.3, and 5.3%, respectively. The bulk moduli of the polyhedral sites are 293(15) GPa
for the tetrahedron, 106(5) GPa for the M2 octahedron, 113(2) GPa for the M3 octahedron, and 113(3) GPa for the total void
space. The bulk modulus exhibits a good linear correlation with the filling factor for polyhedral sites in structures of the
humite minerals and forsterite, reflecting the Si4+ + 4O2− ⇔ □ + 4(OH, F)− substitution in the humite minerals. Moreover, two simply linear trends were observed in the relationship between bulk modulus
and packing index for natural minerals and dense hydrous magnesium silicate minerals. This relationship would reflect that
the differences in compression mechanism were involved with hydrogen bonding in these minerals.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
18.
D. W. Fan M. N. Ma W. G. Zhou S. Y. Wei Z. Q. Chen H. S. Xie 《Physics and Chemistry of Minerals》2011,38(2):95-99
The high-pressure X-ray diffraction study of a natural arsenopyrite was investigated up to 28.2 GPa using in situ angle-dispersive
X-ray diffraction and a diamond anvil cell at National Synchrotron Light Source, Brookhaven National Laboratory. The 16:3:1
methanol–ethanol–water mixture was used as a pressure-transmitting medium. Pressures were measured using the ruby-fluorescence
method. No phase change has been observed up to 28.2 GPa. The isothermal equation of state (EOS) was determined. The values
of K
0, and K′
0 refined with a third-order Birch–Murnaghan EOS are K
0 = 123(9) GPa, and K′
0 = 5.2(8). Furthermore, we confirm that the linear compressibilities (β) along a, b and c directions of arsenopyrite is elastically isotropic (β
a
= 6.82 × 10−4, β
b
= 6.17 × 10−4 and β
c
= 6.57 × 10−4 GPa−1). 相似文献
19.
C. M. Holl J. R. Smyth M. H. Manghnani G. M. Amulele M. Sekar D. J. Frost V. B. Prakapenka G. Shen 《Physics and Chemistry of Minerals》2006,33(3):192-199
Fe-bearing dense hydrous magnesium silicate Phase A, Mg6.85Fe0.14Si2.00O8(OH)6 has been studied by single-crystal X-ray diffraction at ambient conditions and by high-pressure powder diffraction using synchrotron radiation to 33 GPa. Unit cell parameters at room temperature and pressure from single crystal diffraction are a=7.8678 (4) Å, c=9.5771 (5) Å, and V=513.43 (4) Å3. Fitting of the P–V data to a third-order Birch-Murnaghan isothermal equation of state yields V
0=512.3 (3) Å3, K
T,0=102.9 (28) GPa and K′=6.4 (3). Compression is strongly anisotropic with the a-axes, which lie in the plane of the distorted close-packed layers, approximately 26% more compressible than the c-axis, which is normal to the plane. Structure refinement from single-crystal X-ray intensity data reveals expansion of the structure with Fe substitution, mainly by expansion of M-site octahedra. The short Si2–O6 distance becomes nearly 1% shorter with ~2% Fe substitution for Mg, possibly providing additional rigidity in the c-direction over the Mg end member. K
T obtained for the Fe-bearing sample is ~5.5% greater than reported previously for Fe-free Phase A, despite the larger unit cell volume. This study represents a direct comparison of structure and K
T–ρ relations between two compositions of a F-free dense hydrous magnesium silicate (DHMS) phase, and may help to characterize the effect of Fe substitution on the properties of other DHMS phases from studies of the Fe-free end-members. 相似文献
20.
Akio Suzuki 《Physics and Chemistry of Minerals》2010,37(3):153-157
An in situ synchrotron X-ray diffraction study was carried out on ε-FeOOH at room temperature up to a pressure of 8.6 GPa
using the energy-dispersive method. The linear compressibility was determined to be β
a
= 1.69(3) × 10−3 GPa−1, β
b
= 2.86(6) × 10−3 GPa−1, and β
c
= 1.73(5) × 10−3 GPa−1. The b-axis of the unit cell is more compressible than the a and c axes. The pressure–volume data were fitted to a third-order Birch–Murnaghan equation of state. The best fit was found using
a room temperature isothermal bulk modulus of K
0 = 126(3) GPa and its pressure derivative K′ = 10(1). 相似文献