(K
xNa
1-x)NbO
3 ceramics modified with Li
+ and Ta
5+ have been produced using the mixed-oxide synthesis method. Synchrotron X-ray diffraction measurements were made on the samples from 12 K to temperatures above their ferroelectric-paraelectric transition points with 10 K measurement steps. Rietveld refinement was used to refine the patterns. Depending on the composition and temperature, rhombohedral phases, orthorhombic phases, tetragonal phases, cubic phases and two-phase mixtures were obtained. Space groups
R3
c (161),
Amm2 (38),
P4
mm (99) and
(221) and their combinations were used to refine the rhombohedral, orthorhombic, tetragonal, cubic and mixed phases, respectively. Li
+ addition suppressed the formation of the rhombohedral low-temperature phase and increased the Curie temperature. This is attributed to the size difference in ionic radii of the
A-site elements, which leads to increased atomic polarizability and increased interaction with the
B-site element. Li
+ and Ta
5+ co-doping led to a wide temperature range of coexistence between the orthorhombic and tetragonal phases. Electrical characterizations by dielectric and hysteresis measurements were used to compare with the results from the structural studies.
Supporting information
| Crystallographic Information File (CIF) https://doi.org/10.1107/S0021889811027701/cg5189sup1.cif Contains datablocks global, KNN-L_12K |
| Rietveld powder data file (CIF format) https://doi.org/10.1107/S0021889811027701/cg5189KNN-L_12Ksup2.rtv Contains datablock KNN-L_12K |
| Crystallographic Information File (CIF) https://doi.org/10.1107/S0021889811027701/cg5189sup3.cif Contains datablocks global, KNN-L_373K, Tetragonal |
| Rietveld powder data file (CIF format) https://doi.org/10.1107/S0021889811027701/cg5189KNN-L_373Ksup4.rtv Contains datablock KNN-L_373K |
| Crystallographic Information File (CIF) https://doi.org/10.1107/S0021889811027701/cg5189sup5.cif Contains datablocks global, KNN-L_393K |
| Rietveld powder data file (CIF format) https://doi.org/10.1107/S0021889811027701/cg5189KNN-L_393Ksup6.rtv Contains datablock KNN-L_393K |
| Crystallographic Information File (CIF) https://doi.org/10.1107/S0021889811027701/cg5189sup7.cif Contains datablocks global, KNN-L_753K |
| Rietveld powder data file (CIF format) https://doi.org/10.1107/S0021889811027701/cg5189KNN-L_753Ksup8.rtv Contains datablock KNN-L_753K |
| Crystallographic Information File (CIF) https://doi.org/10.1107/S0021889811027701/cg5189sup9.cif Contains datablocks global, KNN-T_12K |
| Rietveld powder data file (CIF format) https://doi.org/10.1107/S0021889811027701/cg5189KNN-T_12Ksup10.rtv Contains datablock KNN-T_12K |
| Crystallographic Information File (CIF) https://doi.org/10.1107/S0021889811027701/cg5189sup11.cif Contains datablocks global, KNN-T_170K, orthorhombic |
| Rietveld powder data file (CIF format) https://doi.org/10.1107/S0021889811027701/cg5189KNN-T_170Ksup12.rtv Contains datablock KNN-T_170K |
| Crystallographic Information File (CIF) https://doi.org/10.1107/S0021889811027701/cg5189sup13.cif Contains datablocks global, KNN-T_190K |
| Rietveld powder data file (CIF format) https://doi.org/10.1107/S0021889811027701/cg5189KNN-T_190Ksup14.rtv Contains datablock KNN-T_190K |
| Crystallographic Information File (CIF) https://doi.org/10.1107/S0021889811027701/cg5189sup15.cif Contains datablocks global, KNN-T_443K |
| Rietveld powder data file (CIF format) https://doi.org/10.1107/S0021889811027701/cg5189KNN-T_443Ksup16.rtv Contains datablock KNN-T_443K |
| Crystallographic Information File (CIF) https://doi.org/10.1107/S0021889811027701/cg5189sup17.cif Contains datablocks global, KNN-T_643K |
| Rietveld powder data file (CIF format) https://doi.org/10.1107/S0021889811027701/cg5189KNN-T_643Ksup18.rtv Contains datablock KNN-T_643K |
| Crystallographic Information File (CIF) https://doi.org/10.1107/S0021889811027701/cg5189sup19.cif Contains datablocks global, KNN-LT_12K |
| Rietveld powder data file (CIF format) https://doi.org/10.1107/S0021889811027701/cg5189KNN-LT_12Ksup20.rtv Contains datablock KNN-LT_12K |
| Crystallographic Information File (CIF) https://doi.org/10.1107/S0021889811027701/cg5189sup21.cif Contains datablocks global, KNN-LT_293K, Tetragonal |
| Rietveld powder data file (CIF format) https://doi.org/10.1107/S0021889811027701/cg5189KNN-LT_293Ksup22.rtv Contains datablock KNN-LT_293K |
| Crystallographic Information File (CIF) https://doi.org/10.1107/S0021889811027701/cg5189sup23.cif Contains datablocks global, KNN-LT_383K |
| Rietveld powder data file (CIF format) https://doi.org/10.1107/S0021889811027701/cg5189KNN-LT_383Ksup24.rtv Contains datablock KNN-LT_383K |
| Crystallographic Information File (CIF) https://doi.org/10.1107/S0021889811027701/cg5189sup25.cif Contains datablocks global, KNN-LT_693K |
| Rietveld powder data file (CIF format) https://doi.org/10.1107/S0021889811027701/cg5189KNN-LT_693Ksup26.rtv Contains datablock KNN-LT_693K |
Program(s) used to refine structure: FULLPROF.
Crystal data top
Orthorhombic, Amm2 | c = 5.68307 (5) Å |
Hall symbol: A 2 -2 | V = 125.99 (1) Å3 |
a = 3.93132 (3) Å | X-ray radiation |
b = 5.63895 (5) Å | |
Data collection top
2θmin = 5.000°, 2θmax = 70.000°, 2θstep = 0.004° | |
Refinement top
Rp = 7.609 | 16251 data points |
Rwp = 10.017 | 35 parameters |
Rexp = 2.140 | 0 restraints |
RBragg = 6.752 | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
O1 | 0.50000 | 0.25000 | 0.289 (2) | 0.0021 (8)* | |
O2 | 0.00000 | 0.00000 | 0.5475 (19) | 0.0021 (8)* | 0.99998 |
Na | 0.00000 | 0.00000 | 0.00000 | 0.0056 (4)* | 0.50830 |
K | 0.00000 | 0.00000 | 0.00000 | 0.0056 (4)* | 0.46844 |
Li | 0.00000 | 0.00000 | 0.00000 | 0.0056 (4)* | 0.02990 |
Zr | 0.00000 | 0.00000 | 0.00000 | 0.0056 (4)* | 0.00020 |
Nb | 0.50000 | 0.00000 | 0.5041 (14) | 0.00008 (16)* | 0.96677 |
Crystal data top
Orthorhombic, Amm2 | c = 5.67707 (8) Å |
Hall symbol: A 2 -2 | V = 126.48 (1) Å3 |
a = 3.94655 (4) Å | X-ray radiation |
b = 5.64505 (8) Å | |
Data collection top
2θmin = 5.000°, 2θmax = 60.000°, 2θstep = 0.004° | |
Refinement top
Rp = 11.635 | 13751 data points |
Rwp = 14.973 | 35 parameters |
Rexp = 2.286 | 0 restraints |
RBragg = 11.820 | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
O_1 | 0.50000 | 0.25000 | 0.297 (3) | 0.0028 (12)* | |
O_2 | 0.00000 | 0.00000 | 0.558 (2) | 0.0028 (12)* | |
Na | 0.00000 | 0.00000 | 0.00000 | 0.0110 (9)* | 0.49787 |
K | 0.00000 | 0.00000 | 0.00000 | 0.0110 (9)* | 0.43465 |
Li | 0.00000 | 0.00000 | 0.00000 | 0.0110 (9)* | 0.01316 |
Zr | 0.00000 | 0.00000 | 0.00000 | 0.0110 (9)* | 0.00458 |
Nb | 0.50000 | 0.00000 | 0.5149 (17) | 0.050063 (4)* | 0.98783 |
Crystal data top
Tetragonal, P4mm | c = 4.0454 (6) Å |
Hall symbol: P 4 -2 | V = 63.21 (1) Å3 |
a = 3.9528 (3) Å | X-ray radiation |
Data collection top
2θmin = 5.000°, 2θmax = 60.000°, 2θstep = 0.004° | |
Refinement top
Rp = 11.635 | 0 data points |
Rwp = 14.973 | 35 parameters |
Rexp = 2.286 | 0 restraints |
RBragg = 50.624 | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
O_1 | 0.50000 | 0.25000 | 0.290 (3) | 0.0028 (12)* | |
O_2 | 0.00000 | 0.00000 | 0.551 (2) | 0.0028 (12)* | |
Na | 0.00000 | 0.00000 | 0.00000 | 0.0110 (9)* | |
K | 0.00000 | 0.00000 | 0.00000 | 0.0110 (9)* | 0.93687 |
Li | 0.00000 | 0.00000 | 0.00000 | 0.0110 (9)* | 0.05980 |
Zr | 0.00000 | 0.00000 | 0.00000 | 0.0110 (9)* | 0.00040 |
Nb | 0.50000 | 0.00000 | 0.5103 (17) | 0.050063 (4)* | 0.96677 |
Crystal data top
Tetragonal, P4mm | c = 4.03898 (4) Å |
Hall symbol: P 4 -2 | V = 63.19 (1) Å3 |
a = 3.95531 (3) Å | X-ray radiation |
Data collection top
2θmin = 5.000°, 2θmax = 60.000°, 2θstep = 0.004° | |
Refinement top
Rp = 12.547 | 13751 data points |
Rwp = 16.838 | 30 parameters |
Rexp = 2.308 | 0 restraints |
RBragg = 13.771 | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
O_1 | 0.00000 | 0.50000 | 0.549 (4) | 0.0057 (12)* | |
O_2 | 0.50000 | 0.50000 | −0.050 (5) | 0.0057 (12)* | |
Na | 0.00000 | 0.00000 | 0.00000 | 0.0210 (8)* | 0.50829 |
K | 0.00000 | 0.00000 | 0.00000 | 0.0210 (8)* | 0.46843 |
Li | 0.00000 | 0.00000 | 0.00000 | 0.0210 (8)* | 0.02990 |
Zr | 0.00000 | 0.00000 | 0.00000 | 0.0210 (8)* | 0.00040 |
Nb | 0.50000 | 0.50000 | 0.493 (4) | 0.0102 (3)* | 0.96675 |
Crystal data top
Cubic, Pm3m | V = 63.38 (1) Å3 |
Hall symbol: -P 4 2 3 | X-ray radiation |
a = 3.98709 (2) Å | |
Data collection top
2θmin = 5.000°, 2θmax = 60.000°, 2θstep = 0.004° | |
Refinement top
Rp = 11.674 | 13751 data points |
Rwp = 14.700 | 20 parameters |
Rexp = 2.356 | 0 restraints |
RBragg = 16.931 | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
O | 0.50000 | 0.50000 | 0.00000 | 0.019105 (4)* | |
Na | 0.00000 | 0.00000 | 0.00000 | 0.0357 (7)* | 0.50853 |
K | 0.00000 | 0.00000 | 0.00000 | 0.0357 (7)* | 0.46835 |
Li | 0.00000 | 0.00000 | 0.00000 | 0.0357 (7)* | 0.03014 |
Zr | 0.00000 | 0.00000 | 0.00000 | 0.0357 (7)* | 0.00239 |
Nb | 0.50000 | 0.50000 | 0.50000 | 0.0212 (3)* | 0.96635 |
Crystal data top
Rhombohedral, R3c | α = 90° |
Hall symbol: R 3 -2"c | γ = 120° |
a = 5.612706 (1) Å | V = 377.42 (1) Å3 |
c = 13.83390 Å | X-ray radiation |
Data collection top
2θmin = 5.000°, 2θmax = 70.000°, 2θstep = 0.004° | |
Refinement top
Rp = 6.397 | 16251 data points |
Rwp = 8.343 | 27 parameters |
Rexp = 1.914 | 0 restraints |
RBragg = 6.681 | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
O | 0.16667 | 0.33333 | 0.83333 | 0.0046 (9)* | |
Na | 0.00000 | 0.00000 | 0.0170 (8) | 0.0007 (4)* | 0.50626 |
K | 0.00000 | 0.00000 | 0.0170 (8) | 0.0007 (4)* | 0.48460 |
Zr | 0.00000 | 0.00000 | 0.0170 (8) | 0.0007 (4)* | 0.00080 |
Nb | 0.00000 | 0.00000 | 0.2630 (4) | −0.00025 (13)* | 0.87787 |
Ta | 0.00000 | 0.00000 | 0.2630 (4) | −0.00025 (13)* | 0.09794 |
Crystal data top
Rhombohedral, R3c | α = 90° |
Hall symbol: R 3 -2"c | γ = 120° |
a = 5.616620 (1) Å | V = 377.91 (1) Å3 |
c = 13.83255 Å | X-ray radiation |
Data collection top
2θmin = 5.000°, 2θmax = 70.000°, 2θstep = 0.004° | |
Refinement top
Rp = 6.504 | 16251 data points |
Rwp = 8.561 | 35 parameters |
Rexp = 1.884 | 0 restraints |
RBragg = 6.376 | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
O | 0.16667 | 0.33333 | 0.83333 | −0.0021 (10)* | |
Na | 0.00000 | 0.00000 | 0.0214 (8) | −0.0077 (6)* | 0.53520 |
K | 0.00000 | 0.00000 | 0.0214 (8) | −0.0077 (6)* | 0.38601 |
Li | 0.00000 | 0.00000 | 0.0214 (8) | −0.0077 (6)* | 0.03000 |
Zr | 0.00000 | 0.00000 | 0.0214 (8) | −0.0077 (6)* | 0.00180 |
Nb | 0.00000 | 0.00000 | 0.2646 (5) | 0.00377 (16)* | 0.90000 |
Ta | 0.00000 | 0.00000 | 0.2646 (5) | 0.00377 (16)* | 0.10800 |
Sb | 0.00000 | 0.00000 | 0.2646 (5) | 0.00377 (16)* | 0.02907 |
Crystal data top
Orthorhombic, Amm2 | c = 5.67068 (10) Å |
Hall symbol: A 2 -2 | V = 125.97 (1) Å3 |
a = 3.94036 (6) Å | X-ray radiation |
b = 5.63778 (12) Å | |
Data collection top
2θmin = 5.000°, 2θmax = 70.000°, 2θstep = 0.004° | |
Refinement top
Rp = 6.504 | 0 data points |
Rwp = 8.561 | 35 parameters |
Rexp = 1.884 | 0 restraints |
RBragg = 8.835 | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
O1 | 0.50000 | 0.25000 | 0.3 (6) | −0.0021 (10)* | |
O2 | 0.00000 | 0.00000 | 0.6 (6) | −0.0021 (10)* | 0.99998 |
Na | 0.00000 | 0.00000 | 0.0 (6) | −0.0077 (6)* | 0.53395 |
K | 0.00000 | 0.00000 | 0.0 (6) | −0.0077 (6)* | 0.38510 |
Li | 0.00000 | 0.00000 | 0.0 (6) | −0.0077 (6)* | 0.02993 |
Zr | 0.00000 | 0.00000 | 0.0 (6) | −0.0077 (6)* | 0.00180 |
Nb | 0.50000 | 0.00000 | 0.5 (6) | 0.00377 (16)* | 0.89790 |
Ta | 0.50000 | 0.00000 | 0.5 (6) | 0.00377 (16)* | 0.10775 |
Sb | 0.50000 | 0.00000 | 0.5 (6) | 0.00377 (16)* | 0.02901 |
Crystal data top
Orthorhombic, Amm2 | c = 5.67081 (4) Å |
Hall symbol: A 2 -2 | V = 126.00 (1) Å3 |
a = 3.94128 (2) Å | X-ray radiation |
b = 5.63739 (4) Å | |
Data collection top
2θmin = 5.000°, 2θmax = 70.000°, 2θstep = 0.004° | |
Refinement top
Rp = 6.341 | 16251 data points |
Rwp = 8.229 | 35 parameters |
Rexp = 1.886 | 0 restraints |
RBragg = 6.828 | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
O1 | 0.50000 | 0.25000 | 0.289 (2) | 0.0023 (9)* | |
O2 | 0.00000 | 0.00000 | 0.549 (2) | 0.0023 (9)* | |
Na | 0.00000 | 0.00000 | 0.00000 | 0.0069 (5)* | 0.50663 |
K | 0.00000 | 0.00000 | 0.00000 | 0.0069 (5)* | 0.48676 |
Zr | 0.00000 | 0.00000 | 0.00000 | 0.0069 (5)* | 0.00020 |
Nb | 0.50000 | 0.00000 | 0.5079 (17) | 0.00188 (16)* | 0.87418 |
Ta | 0.50000 | 0.00000 | 0.5079 (17) | 0.00188 (16)* | 0.09934 |
Crystal data top
Tetragonal, P4mm | c = 4.01987 (3) Å |
Hall symbol: P 4 -2 | V = 63.13 (1) Å3 |
a = 3.96291 (2) Å | X-ray radiation |
Data collection top
2θmin = 5.000°, 2θmax = 60.000°, 2θstep = 0.004° | |
Refinement top
Rp = 8.826 | 13751 data points |
Rwp = 11.404 | 30 parameters |
Rexp = 2.213 | 0 restraints |
RBragg = 10.085 | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
O_1 | 0.00000 | 0.50000 | 0.554 (5) | 0.0101 (10)* | |
O_2 | 0.50000 | 0.50000 | −0.019 (7) | 0.0101 (10)* | 0.99996 |
Na | 0.00000 | 0.00000 | 0.00000 | 0.0202 (6)* | 0.50662 |
K | 0.00000 | 0.00000 | 0.00000 | 0.0202 (6)* | 0.48675 |
Zr | 0.00000 | 0.00000 | 0.00000 | 0.0202 (6)* | 0.00040 |
Nb | 0.50000 | 0.50000 | 0.505 (5) | 0.0094 (2)* | 0.87416 |
Ta | 0.50000 | 0.50000 | 0.505 (5) | 0.0094 (2)* | 0.09934 |
Crystal data top
Cubic, Pm3m | V = 63.18 (1) Å3 |
Hall symbol: -P 4 2 3 | X-ray radiation |
a = 3.982755 (19) Å | |
Data collection top
2θmin = 5.000°, 2θmax = 60.000°, 2θstep = 0.004° | |
Refinement top
Rp = 9.215 | 13751 data points |
Rwp = 12.118 | 20 parameters |
Rexp = 2.205 | 0 restraints |
RBragg = 11.795 | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
O | 0.50000 | 0.50000 | 0.00000 | 0.018991 (3)* | |
Na | 0.00000 | 0.00000 | 0.00000 | 0.0280 (6)* | 0.50683 |
K | 0.00000 | 0.00000 | 0.00000 | 0.0280 (6)* | 0.48633 |
Zr | 0.00000 | 0.00000 | 0.00000 | 0.0280 (6)* | 0.00238 |
Nb | 0.50000 | 0.50000 | 0.50000 | 0.0161 (2)* | 0.87397 |
Ta | 0.50000 | 0.50000 | 0.50000 | 0.0161 (2)* | 0.09917 |
Crystal data top
Orthorhombic, Amm2 | c = 5.67188 (6) Å |
Hall symbol: A 2 -2 | V = 125.76 (1) Å3 |
a = 3.93602 (3) Å | X-ray radiation |
b = 5.63331 (6) Å | |
Data collection top
2θmin = 5.000°, 2θmax = 70.000°, 2θstep = 0.004° | |
Refinement top
Rp = 6.264 | 16251 data points |
Rwp = 8.058 | 35 parameters |
Rexp = 1.814 | 0 restraints |
RBragg = 6.366 | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
O1 | 0.50000 | 0.25000 | 0.287 (3) | 0.0002 (9)* | |
O2 | 0.00000 | 0.00000 | 0.550 (2) | 0.0002 (9)* | |
Na | 0.00000 | 0.00000 | 0.00000 | 0.0023 (5)* | 0.50663 |
K | 0.00000 | 0.00000 | 0.00000 | 0.0023 (5)* | 0.46689 |
Li | 0.00000 | 0.00000 | 0.00000 | 0.0023 (5)* | 0.02980 |
Zr | 0.00000 | 0.00000 | 0.00000 | 0.0023 (5)* | 0.00103 |
Nb | 0.50000 | 0.00000 | 0.5068 (18) | −0.00222 (15)* | 0.87418 |
Ta | 0.50000 | 0.00000 | 0.5068 (18) | −0.00222 (15)* | 0.09934 |
Crystal data top
Orthorhombic, Amm2 | c = 5.66929 (11) Å |
Hall symbol: A 2 -2 | V = 126.21 (1) Å3 |
a = 3.94594 (5) Å | X-ray radiation |
b = 5.6418 (2) Å | |
Data collection top
2θmin = 5.000°, 2θmax = 60.000°, 2θstep = 0.004° | |
Refinement top
Rp = 4.496 | 13751 data points |
Rwp = 5.699 | 46 parameters |
Rexp = 1.510 | 0 restraints |
RBragg = 12.510 | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
O_1 | 0.50000 | 0.25000 | 0.266 (6) | 0.005 (3)* | |
O_2 | 0.00000 | 0.00000 | 0.535 (5) | 0.005 (3)* | |
Na | 0.00000 | 0.00000 | 0.00000 | 0.015 (2)* | 0.50663 |
K | 0.00000 | 0.00000 | 0.00000 | 0.015 (2)* | 0.46689 |
Li | 0.00000 | 0.00000 | 0.00000 | 0.015 (2)* | 0.02980 |
Zr | 0.00000 | 0.00000 | 0.00000 | 0.015 (2)* | 0.00020 |
Nb | 0.50000 | 0.00000 | 0.489 (4) | 0.0040 (5)* | 0.87418 |
Ta | 0.50000 | 0.00000 | 0.489 (4) | 0.0040 (5)* | 0.09934 |
Crystal data top
Tetragonal, P4mm | c = 4.0038 (5) Å |
Hall symbol: P 4 -2 | V = 62.63 (1) Å3 |
a = 3.95505 (12) Å | X-ray radiation |
Data collection top
2θmin = 5.000°, 2θmax = 60.000°, 2θstep = 0.004° | |
Refinement top
Rp = 4.496 | 0 data points |
Rwp = 5.699 | 46 parameters |
Rexp = 1.510 | 0 restraints |
RBragg = 16.114 | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
O_1 | 0.00000 | 0.50000 | 0.57 (2) | 0.000 (5)* | |
O_2 | 0.50000 | 0.50000 | 0.04 (3) | 0.000 (5)* | 0.99996 |
Na | 0.00000 | 0.00000 | 0.00000 | 0.005 (3)* | 0.50662 |
K | 0.00000 | 0.00000 | 0.00000 | 0.005 (3)* | 0.46688 |
Li | 0.00000 | 0.00000 | 0.00000 | 0.005 (3)* | 0.02980 |
Zr | 0.00000 | 0.00000 | 0.00000 | 0.005 (3)* | 0.00040 |
Nb | 0.50000 | 0.50000 | 0.501 (16) | 0.0101 (14)* | 0.87416 |
Ta | 0.50000 | 0.50000 | 0.501 (16) | 0.0101 (14)* | 0.09934 |
Crystal data top
Tetragonal, P4mm | c = 4.02479 (3) Å |
Hall symbol: P 4 -2 | V = 62.95 (1) Å3 |
a = 3.95496 (2) Å | X-ray radiation |
Data collection top
2θmin = 5.000°, 2θmax = 60.000°, 2θstep = 0.004° | |
Refinement top
Rp = 6.079 | 13751 data points |
Rwp = 8.051 | 30 parameters |
Rexp = 1.213 | 0 restraints |
RBragg = 8.644 | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
O_1 | 0.00000 | 0.50000 | 0.570 (2) | 0.0075 (8)* | |
O_2 | 0.50000 | 0.50000 | 0.049 (4) | 0.0075 (8)* | 0.99996 |
Na | 0.00000 | 0.00000 | 0.00000 | 0.0163 (6)* | 0.50662 |
K | 0.00000 | 0.00000 | 0.00000 | 0.0163 (6)* | 0.46688 |
Li | 0.00000 | 0.00000 | 0.00000 | 0.0163 (6)* | 0.02980 |
Zr | 0.00000 | 0.00000 | 0.00000 | 0.0163 (6)* | 0.00040 |
Nb | 0.50000 | 0.50000 | 0.517 (2) | 0.00686 (16)* | 0.87416 |
Ta | 0.50000 | 0.50000 | 0.517 (2) | 0.00686 (16)* | 0.09934 |
Crystal data top
Cubic, Pm3m | V = 63.09 (1) Å3 |
Hall symbol: -P 4 2 3 | X-ray radiation |
a = 3.98094 (2) Å | |
Data collection top
2θmin = 5.000°, 2θmax = 60.000°, 2θstep = 0.004° | |
Refinement top
Rp = 7.044 | 13751 data points |
Rwp = 9.059 | 23 parameters |
Rexp = 1.740 | 0 restraints |
RBragg = 9.325 | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
O | 0.50000 | 0.50000 | 0.00000 | 0.0180 (7)* | |
Na | 0.00000 | 0.00000 | 0.00000 | 0.0282 (6)* | 0.50683 |
K | 0.00000 | 0.00000 | 0.00000 | 0.0282 (6)* | 0.46678 |
Li | 0.00000 | 0.00000 | 0.00000 | 0.0282 (6)* | 0.03004 |
Nb | 0.50000 | 0.50000 | 0.50000 | 0.01307 (19)* | 0.87397 |
Ta | 0.50000 | 0.50000 | 0.50000 | 0.01307 (19)* | 0.09917 |
Zr | 0.00000 | 0.00000 | 0.00000 | 0.0282 (6)* | 0.00238 |