The crystal and local atomic structure of monoclinic ReO2 (α-ReO2) under hydrostatic pressure up to 1.2 GPa was investigated for the first time using both X-ray absorption spectroscopy and high-resolution synchrotron X-ray powder diffraction and a home-built B4C anvil pressure cell developed for this purpose. Extended X-ray absorption fine-structure (EXAFS) data analysis at pressures from ambient up to 1.2 GPa indicates that there are two distinct Re—Re distances and a distorted ReO6 octahedron in the α-ReO2 structure. X-ray diffraction analysis at ambient pressure revealed an unambiguous solution for the crystal structure of the α-phase, demonstrating a modulation of the Re—Re distances. The relatively small portion of the diffraction pattern accessed in the pressure-dependent measurements does not allow for a detailed study of the crystal structure of α-ReO2 under pressure. Nonetheless, a shift and reduction in the (011) Bragg peak intensity between 0.4 and 1.2 GPa is observed, with correlation to a decrease in Re—Re distance modulation, as confirmed by EXAFS analysis in the same pressure range. This behavior reveals that α-ReO2 is a possible inner pressure gauge for future experiments up to 1.2 GPa.
Supporting information
Crystal data top
O2Re | β = 120.2721 (18)° |
Mr = 218.21 | V = 129.17 (1) Å3 |
Monoclinic, P21/c | Z = 4 |
a = 5.61113 (15) Å | ? radiation, λ = 1.239998 Å |
b = 4.80456 (9) Å | ?, ? × ? × ? mm |
c = 5.54783 (17) Å | |
Data collection top
2θmin = 13.998°, 2θmax = 99.988°, 2θstep = 0.01° | |
Refinement top
Least-squares matrix: full | 8600 data points |
Rp = 0.092 | Profile function: CW Profile function number 4 with 21 terms
Pseudovoigt profile coefficients as parameterized in
P. Thompson, D.E. Cox & J.B. Hastings (1987). J. Appl. Cryst.,20,79-83.
Asymmetry correction of L.W. Finger, D.E. Cox & A. P. Jephcoat (1994).
J. Appl. Cryst.,27,892-900.
Microstrain broadening by P.W. Stephens, (1999). J. Appl. Cryst.,32,281-289.
#1(GU) = 0.000 #2(GV) = 0.000 #3(GW) = 0.000
#4(GP) = 0.000 #5(LX) = 2.858 #6(ptec) = 0.00
#7(trns) = 0.00 #8(shft) = 0.3326 #9(sfec) = 0.00
#10(S/L) = 0.0063 #11(H/L) = 0.0063 #12(eta) = 0.4445
#13(S400 ) = 2.2E+00 #14(S040 ) = 6.8E+00 #15(S004 ) = 7.4E+00
#16(S220 ) = 3.5E-01 #17(S202 ) = 5.9E+00 #18(S022 ) = -3.1E+00
#19(S301 ) = 4.4E+00 #20(S103 ) = 5.9E+00 #21(S121 ) = -3.3E-01
Peak tails are ignored where the intensity is below 0.0010 times the peak
Aniso. broadening axis 0.0 0.0 1.0, CW Profile function number 4 with 16 terms
Pseudovoigt profile coefficients as parameterized in
P. Thompson, D.E. Cox & J.B. Hastings (1987). J. Appl. Cryst.,20,79-83.
Asymmetry correction of L.W. Finger, D.E. Cox & A. P. Jephcoat (1994).
J. Appl. Cryst.,27,892-900.
Microstrain broadening by P.W. Stephens, (1999). J. Appl. Cryst.,32,281-289.
#1(GU) = 0.000 #2(GV) = 0.000 #3(GW) = 0.000
#4(GP) = 0.000 #5(LX) = 2.680 #6(ptec) = 0.00
#7(trns) = 0.00 #8(shft) = 0.3326 #9(sfec) = 0.00
#10(S/L) = 0.0063 #11(H/L) = 0.0063 #12(eta) = 0.9810
#13(S400 ) = 4.1E-02 #14(S004 ) = 3.0E-05
#15(S220 ) = -2.6E-02 #16(S202 ) = 6.3E-01
Peak tails are ignored where the intensity is below 0.0010 times the peak
Aniso. broadening axis 0.0 0.0 1.0, CW Profile function number 4 with 18 terms
Pseudovoigt profile coefficients as parameterized in
P. Thompson, D.E. Cox & J.B. Hastings (1987). J. Appl. Cryst.,20,79-83.
Asymmetry correction of L.W. Finger, D.E. Cox & A. P. Jephcoat (1994).
J. Appl. Cryst.,27,892-900.
Microstrain broadening by P.W. Stephens, (1999). J. Appl. Cryst.,32,281-289.
#1(GU) = 0.000 #2(GV) = 0.000 #3(GW) = 0.000
#4(GP) = 0.000 #5(LX) = 10.115 #6(ptec) = 0.00
#7(trns) = 0.00 #8(shft) = 0.3326 #9(sfec) = 0.00
#10(S/L) = 0.0063 #11(H/L) = 0.0063 #12(eta) = 0.6973
#13(S400 ) = 7.4E-01 #14(S040 ) = 2.2E+00 #15(S004 ) = 3.8E+00
#16(S220 ) = 7.7E-01 #17(S202 ) = -6.7E-01 #18(S022 ) = 5.0E-01
Peak tails are ignored where the intensity is below 0.0010 times the peak
Aniso. broadening axis 0.0 0.0 1.0 |
Rwp = 0.121 | 57 parameters |
Rexp = 0.091 | 0 restraints |
R(F2) = 0.05927 | (Δ/σ)max = 0.05 |
χ2 = 1.769 | Background function: GSAS Background function number 1 with 14 terms.
Shifted Chebyshev function of 1st kind
1: 43.6672 2: -14.9861 3: 2.15605 4: -1.46007
5: -0.693433 6: 2.03766 7: -3.19664 8: 3.10886
9: -0.434656 10: -1.86818 11: 4.98375 12: -3.92371
13: 1.06103 14: -0.269726 |
Crystal data top
O2Re | β = 120.2721 (18)° |
Mr = 218.21 | V = 129.17 (1) Å3 |
Monoclinic, P21/c | Z = 4 |
a = 5.61113 (15) Å | ? radiation, λ = 1.239998 Å |
b = 4.80456 (9) Å | ?, ? × ? × ? mm |
c = 5.54783 (17) Å | |
Data collection top
2θmin = 13.998°, 2θmax = 99.988°, 2θstep = 0.01° | |
Refinement top
Rp = 0.092 | χ2 = 1.769 |
Rwp = 0.121 | 8600 data points |
Rexp = 0.091 | 57 parameters |
R(F2) = 0.05927 | 0 restraints |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Re1 | 0.2379 (2) | −0.0026 (15) | 0.0067 (3) | 0.01831 (11)* | |
O1 | 0.112 (5) | 0.200 (5) | 0.227 (4) | 0.01831 (11)* | |
O2 | 0.387 (5) | 0.709 (5) | 0.293 (4) | 0.01831 (11)* | |
Crystal data top
O3Re | V = 105.29 (1) Å3 |
Mr = 234.20 | Z = 2 |
Tetragonal, P4/mbm | ? radiation, λ = 1.239998 Å |
a = 5.30107 (11) Å | ?, ? × ? × ? mm |
c = 3.74690 (16) Å | |
Data collection top
2θmin = 13.998°, 2θmax = 99.988°, 2θstep = 0.01° | |
Refinement top
Least-squares matrix: full | 8600 data points |
Rp = 0.092 | Profile function: CW Profile function number 4 with 21 terms
Pseudovoigt profile coefficients as parameterized in
P. Thompson, D.E. Cox & J.B. Hastings (1987). J. Appl. Cryst.,20,79-83.
Asymmetry correction of L.W. Finger, D.E. Cox & A. P. Jephcoat (1994).
J. Appl. Cryst.,27,892-900.
Microstrain broadening by P.W. Stephens, (1999). J. Appl. Cryst.,32,281-289.
#1(GU) = 0.000 #2(GV) = 0.000 #3(GW) = 0.000
#4(GP) = 0.000 #5(LX) = 2.858 #6(ptec) = 0.00
#7(trns) = 0.00 #8(shft) = 0.3326 #9(sfec) = 0.00
#10(S/L) = 0.0063 #11(H/L) = 0.0063 #12(eta) = 0.4445
#13(S400 ) = 2.2E+00 #14(S040 ) = 6.8E+00 #15(S004 ) = 7.4E+00
#16(S220 ) = 3.5E-01 #17(S202 ) = 5.9E+00 #18(S022 ) = -3.1E+00
#19(S301 ) = 4.4E+00 #20(S103 ) = 5.9E+00 #21(S121 ) = -3.3E-01
Peak tails are ignored where the intensity is below 0.0010 times the peak
Aniso. broadening axis 0.0 0.0 1.0, CW Profile function number 4 with 16 terms
Pseudovoigt profile coefficients as parameterized in
P. Thompson, D.E. Cox & J.B. Hastings (1987). J. Appl. Cryst.,20,79-83.
Asymmetry correction of L.W. Finger, D.E. Cox & A. P. Jephcoat (1994).
J. Appl. Cryst.,27,892-900.
Microstrain broadening by P.W. Stephens, (1999). J. Appl. Cryst.,32,281-289.
#1(GU) = 0.000 #2(GV) = 0.000 #3(GW) = 0.000
#4(GP) = 0.000 #5(LX) = 2.680 #6(ptec) = 0.00
#7(trns) = 0.00 #8(shft) = 0.3326 #9(sfec) = 0.00
#10(S/L) = 0.0063 #11(H/L) = 0.0063 #12(eta) = 0.9810
#13(S400 ) = 4.1E-02 #14(S004 ) = 3.0E-05
#15(S220 ) = -2.6E-02 #16(S202 ) = 6.3E-01
Peak tails are ignored where the intensity is below 0.0010 times the peak
Aniso. broadening axis 0.0 0.0 1.0, CW Profile function number 4 with 18 terms
Pseudovoigt profile coefficients as parameterized in
P. Thompson, D.E. Cox & J.B. Hastings (1987). J. Appl. Cryst.,20,79-83.
Asymmetry correction of L.W. Finger, D.E. Cox & A. P. Jephcoat (1994).
J. Appl. Cryst.,27,892-900.
Microstrain broadening by P.W. Stephens, (1999). J. Appl. Cryst.,32,281-289.
#1(GU) = 0.000 #2(GV) = 0.000 #3(GW) = 0.000
#4(GP) = 0.000 #5(LX) = 10.115 #6(ptec) = 0.00
#7(trns) = 0.00 #8(shft) = 0.3326 #9(sfec) = 0.00
#10(S/L) = 0.0063 #11(H/L) = 0.0063 #12(eta) = 0.6973
#13(S400 ) = 7.4E-01 #14(S040 ) = 2.2E+00 #15(S004 ) = 3.8E+00
#16(S220 ) = 7.7E-01 #17(S202 ) = -6.7E-01 #18(S022 ) = 5.0E-01
Peak tails are ignored where the intensity is below 0.0010 times the peak
Aniso. broadening axis 0.0 0.0 1.0 |
Rwp = 0.121 | 57 parameters |
Rexp = 0.091 | 0 restraints |
R(F2) = 0.05927 | (Δ/σ)max = 0.05 |
χ2 = 1.769 | Background function: GSAS Background function number 1 with 14 terms.
Shifted Chebyshev function of 1st kind
1: 43.6672 2: -14.9861 3: 2.15605 4: -1.46007
5: -0.693433 6: 2.03766 7: -3.19664 8: 3.10886
9: -0.434656 10: -1.86818 11: 4.98375 12: -3.92371
13: 1.06103 14: -0.269726 |
Crystal data top
O3Re | V = 105.29 (1) Å3 |
Mr = 234.20 | Z = 2 |
Tetragonal, P4/mbm | ? radiation, λ = 1.239998 Å |
a = 5.30107 (11) Å | ?, ? × ? × ? mm |
c = 3.74690 (16) Å | |
Data collection top
2θmin = 13.998°, 2θmax = 99.988°, 2θstep = 0.01° | |
Refinement top
Rp = 0.092 | χ2 = 1.769 |
Rwp = 0.121 | 8600 data points |
Rexp = 0.091 | 57 parameters |
R(F2) = 0.05927 | 0 restraints |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Re1 | 0.0 | 0.0 | 0.5 | 0.0175 (11)* | |
O1 | 0.0 | 0.0 | 0.0 | 0.0175 (11)* | |
O2 | 0.102 (9) | 0.602 (9) | 0.5 | 0.0175 (11)* | |
Crystal data top
O2Re | c = 4.6129 (2) Å |
Mr = 218.21 | V = 124.83 (1) Å3 |
Orthorhombic, Pbcn | Z = 4 |
a = 4.8040 (2) Å | ? radiation, λ = 1.239998 Å |
b = 5.6332 (4) Å | ?, ? × ? × ? mm |
Data collection top
2θmin = 13.998°, 2θmax = 99.988°, 2θstep = 0.01° | |
Refinement top
Least-squares matrix: full | 8600 data points |
Rp = 0.092 | Profile function: CW Profile function number 4 with 21 terms
Pseudovoigt profile coefficients as parameterized in
P. Thompson, D.E. Cox & J.B. Hastings (1987). J. Appl. Cryst.,20,79-83.
Asymmetry correction of L.W. Finger, D.E. Cox & A. P. Jephcoat (1994).
J. Appl. Cryst.,27,892-900.
Microstrain broadening by P.W. Stephens, (1999). J. Appl. Cryst.,32,281-289.
#1(GU) = 0.000 #2(GV) = 0.000 #3(GW) = 0.000
#4(GP) = 0.000 #5(LX) = 2.858 #6(ptec) = 0.00
#7(trns) = 0.00 #8(shft) = 0.3326 #9(sfec) = 0.00
#10(S/L) = 0.0063 #11(H/L) = 0.0063 #12(eta) = 0.4445
#13(S400 ) = 2.2E+00 #14(S040 ) = 6.8E+00 #15(S004 ) = 7.4E+00
#16(S220 ) = 3.5E-01 #17(S202 ) = 5.9E+00 #18(S022 ) = -3.1E+00
#19(S301 ) = 4.4E+00 #20(S103 ) = 5.9E+00 #21(S121 ) = -3.3E-01
Peak tails are ignored where the intensity is below 0.0010 times the peak
Aniso. broadening axis 0.0 0.0 1.0, CW Profile function number 4 with 16 terms
Pseudovoigt profile coefficients as parameterized in
P. Thompson, D.E. Cox & J.B. Hastings (1987). J. Appl. Cryst.,20,79-83.
Asymmetry correction of L.W. Finger, D.E. Cox & A. P. Jephcoat (1994).
J. Appl. Cryst.,27,892-900.
Microstrain broadening by P.W. Stephens, (1999). J. Appl. Cryst.,32,281-289.
#1(GU) = 0.000 #2(GV) = 0.000 #3(GW) = 0.000
#4(GP) = 0.000 #5(LX) = 2.680 #6(ptec) = 0.00
#7(trns) = 0.00 #8(shft) = 0.3326 #9(sfec) = 0.00
#10(S/L) = 0.0063 #11(H/L) = 0.0063 #12(eta) = 0.9810
#13(S400 ) = 4.1E-02 #14(S004 ) = 3.0E-05
#15(S220 ) = -2.6E-02 #16(S202 ) = 6.3E-01
Peak tails are ignored where the intensity is below 0.0010 times the peak
Aniso. broadening axis 0.0 0.0 1.0, CW Profile function number 4 with 18 terms
Pseudovoigt profile coefficients as parameterized in
P. Thompson, D.E. Cox & J.B. Hastings (1987). J. Appl. Cryst.,20,79-83.
Asymmetry correction of L.W. Finger, D.E. Cox & A. P. Jephcoat (1994).
J. Appl. Cryst.,27,892-900.
Microstrain broadening by P.W. Stephens, (1999). J. Appl. Cryst.,32,281-289.
#1(GU) = 0.000 #2(GV) = 0.000 #3(GW) = 0.000
#4(GP) = 0.000 #5(LX) = 10.115 #6(ptec) = 0.00
#7(trns) = 0.00 #8(shft) = 0.3326 #9(sfec) = 0.00
#10(S/L) = 0.0063 #11(H/L) = 0.0063 #12(eta) = 0.6973
#13(S400 ) = 7.4E-01 #14(S040 ) = 2.2E+00 #15(S004 ) = 3.8E+00
#16(S220 ) = 7.7E-01 #17(S202 ) = -6.7E-01 #18(S022 ) = 5.0E-01
Peak tails are ignored where the intensity is below 0.0010 times the peak
Aniso. broadening axis 0.0 0.0 1.0 |
Rwp = 0.121 | 57 parameters |
Rexp = 0.091 | 0 restraints |
R(F2) = 0.05927 | (Δ/σ)max = 0.05 |
χ2 = 1.769 | Background function: GSAS Background function number 1 with 14 terms.
Shifted Chebyshev function of 1st kind
1: 43.6672 2: -14.9861 3: 2.15605 4: -1.46007
5: -0.693433 6: 2.03766 7: -3.19664 8: 3.10886
9: -0.434656 10: -1.86818 11: 4.98375 12: -3.92371
13: 1.06103 14: -0.269726 |
Crystal data top
O2Re | c = 4.6129 (2) Å |
Mr = 218.21 | V = 124.83 (1) Å3 |
Orthorhombic, Pbcn | Z = 4 |
a = 4.8040 (2) Å | ? radiation, λ = 1.239998 Å |
b = 5.6332 (4) Å | ?, ? × ? × ? mm |
Data collection top
2θmin = 13.998°, 2θmax = 99.988°, 2θstep = 0.01° | |
Refinement top
Rp = 0.092 | χ2 = 1.769 |
Rwp = 0.121 | 8600 data points |
Rexp = 0.091 | 57 parameters |
R(F2) = 0.05927 | 0 restraints |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Re1 | 0.0 | 0.1089 (4) | 0.25 | 0.0072 (3)* | |
O1 | 0.239 (4) | 0.359 (8) | 0.109 (4) | 0.0072 (3)* | |
Experimental details
| (REO2_phase_1) | (REO2_phase_2) | (REO2_phase_3) |
Crystal data |
Chemical formula | O2Re | O3Re | O2Re |
Mr | 218.21 | 234.20 | 218.21 |
Crystal system, space group | Monoclinic, P21/c | Tetragonal, P4/mbm | Orthorhombic, Pbcn |
Temperature (K) | ? | ? | ? |
a, b, c (Å) | 5.61113 (15), 4.80456 (9), 5.54783 (17) | 5.30107 (11), 5.30107, 3.74690 (16) | 4.8040 (2), 5.6332 (4), 4.6129 (2) |
α, β, γ (°) | 90, 120.2721 (18), 90 | 90, 90, 90 | 90, 90, 90 |
V (Å3) | 129.17 (1) | 105.29 (1) | 124.83 (1) |
Z | 4 | 2 | 4 |
Radiation type | ?, λ = 1.239998 Å | ?, λ = 1.239998 Å | ?, λ = 1.239998 Å |
Specimen shape, size (mm) | ?, ? × ? × ? | ?, ? × ? × ? | ?, ? × ? × ? |
|
Data collection |
Diffractometer | ? | ? | ? |
Specimen mounting | ? | ? | ? |
Data collection mode | ? | ? | ? |
Scan method | ? | ? | ? |
2θ values (°) | 2θmin = 13.998 2θmax = 99.988 2θstep = 0.01 | 2θmin = 13.998 2θmax = 99.988 2θstep = 0.01 | 2θmin = 13.998 2θmax = 99.988 2θstep = 0.01 |
|
Refinement |
R factors and goodness of fit | Rp = 0.092, Rwp = 0.121, Rexp = 0.091, R(F2) = 0.05927, χ2 = 1.769 | Rp = 0.092, Rwp = 0.121, Rexp = 0.091, R(F2) = 0.05927, χ2 = 1.769 | Rp = 0.092, Rwp = 0.121, Rexp = 0.091, R(F2) = 0.05927, χ2 = 1.769 |
No. of data points | 8600 | 8600 | 8600 |
No. of parameters | 57 | 57 | 57 |