1 Introduction
2 Experimental details
3 Results and discussion
3.1 X-ray powder diffraction (XRPD)
Phase | x = 0 | x = 0.4 | x = 0.6 | x = 0.8 |
---|---|---|---|---|
a, Å | 5.4435 (2) | 5.4195 (1) | 5.4087 (1) | 5.3991 (1) |
b, Å | 5.4102 (2) | 5.3971 (1) | 5.3893 (1) | 5.3820 (1) |
c, Å | 32.8640 (9) | 32.8406 (6) | 32.8250 (5) | 32.8097 (6) |
g, 10−3
| 6.14 | 4.14 | 3.59 | 3.17 |
s.g. |
B2cb
|
B2cb
|
B2cb
|
B2cb
|
Cation composition (Bi:Tb:Ti) from EDS analysis | 3.98:0:3.02 | 3.62:0.39:2.99 | 3.39:0.59:3.02 | 3.19:0.80:3.01 |
Bi1/Tb1 | ||||
n Bi/Tb | 1.00 (2) | 0.81/0.19 (2) | 0.71/0.29 (2) | 0.63/0.37 (2) |
x/a | 0 | 0 | 0 | 0 |
y/b | 0.9967 (5) | 0.9965 (4) | 0.9971(4) | 0.9973 (5) |
z/c | 0.0669 (1) | 0.0670 (1) | 0.0668 (1) | 0.0666 (1) |
Beq(Å2) | 0.69 (3) | 0.65 (5) | 0.71 (6) | 0.68 (5) |
Bi2/Tb2 | ||||
n Bi/Tb | 0.99 (2)/- | 0.99/0.01 (2) | 0.98/0.02 (2) | 0.97/0.03 (2) |
x/a | 0.0012 (7) | 0.0015 (6) | 0.0022 (6) | 0.0036 (7) |
y/b | 0.0125 (8) | 0.0129 (6) | 0.0133 (4) | 0.0136 (7) |
z/c | 0.2112 (1) | 0.2110 (2) | 0.2107 (1) | 0.2109 (1) |
Beq(Å2) | 0.67 (3) | 0.57 (3) | 0.64 (2) | 0.62 (4) |
Ti1 | ||||
n | 1.01 (2) | 0.98 (2) | 0.99 (2) | 0.99 (2) |
x/a | 0.028 (2) | 0.030 (1) | 0.0347 (9) | 0.0353 (7) |
y/b | 0 | 0 | 0 | 0 |
z/c | 1/2 | 1/2 | 1/2 | 1/2 |
Beq(Å2) | 0.46 (2) | 0.57 (3) | 0.44 (2) | 0.62 (4) |
Ti2 | ||||
n | 0.99 (1) | 1.01 (2) | 1.02 (2) | 1.00 (2) |
x/a | 0.023 (2) | 0.029 (2) | 0.0035 (12) | 0.0038 (12) |
y/b | 0.0028 (8) | 0.0031 (7) | 0.0039 (6) | 0.0041 (6) |
z/c | 0.3712 (1) | 0.3708 (1) | 0.3705 (2) | 0.3704 (1) |
Beq(Å2) | 0.42 (2) | 0.57 (3) | 0.40 (2) | 0.62 (4) |
O1 | ||||
n | 0.99 (2) | 0.99 (2) | 0.98 (2) | 0.98 (2) |
x/a | 0.3011 (9) | 0.3013 (8) | 0.3082 (8) | 0.3092 (8) |
y/b | 0.268 (1) | 0.2663 (11) | 0.2610 (8) | 0.2622 (9) |
z/c | 0.0040 (3) | 0.0080 (4) | 0.0121 (3) | 0.0110 (2) |
Beq(Å2) | 0.92 (5) | 0.75 (5) | 0.84 (6) | 0.78 (5) |
O2 | ||||
n | 1.02 (2) | 0.98 (2) | 0.99 (2) | 0.98 (2) |
x/a | 0.2835 (12) | 0.271 (2) | 0.2632 (9) | 0.2581 (9) |
y/b | 0.2591 (9) | 0.2521 (8) | 0.2513 (8) | 0.2498 (7) |
z/c | 0.2557 (2) | 0.2562 (3) | 0.2565 (2) | 0.2571 (2) |
Beq(Å2) | 1.01 (5) | 1.07 (4) | 1.01 (5) | 1.02 (4) |
O3 | ||||
n | 0.98 (2) | 0.98 (2) | 0.98 (2) | 0.99 (2) |
x/a | 0.065 (2) | 0.071 (2) | 0.079 (2) | 0.0815 (11) |
y/b | 0.0586 (8) | 0.0531 (7) | 0.0503 (8) | 0.0473 (7) |
z/c | 0.4412 (3) | 0.4409 (2) | 0.4406 (3) | 0.4407 (2) |
Beq(Å2) | 1.26 (6) | 1.17 (3) | 1.22 (2) | 1.21 (4) |
O4 | ||||
n | 0.97 (2) | 0.98 (2) | 0.97 (2) | 0.98(2) |
x/a | 0.0511 (11) | 0.055 (1) | 0.0673 (11) | 0.0661 (11) |
y/b | 0.946 (1) | 0.9522 (8) | 0.9672 (9) | 0.9612 (8) |
z/c | 0.3185 (2) | 0.3190 (2) | 0.3220 (2) | 0.3210 (1) |
Beq(Å2) | 1.44 (6) | 1.50 (3) | 1.39 (2) | 1.32 (4) |
O5 | ||||
n | 0.98 (2) | 0.97 (2) | 0.97 (2) | 0.97 (2) |
x/a | 0.2842 (12) | 0.2837 (9) | 0.2829 (11) | 0.2031 (9) |
y/b | 0.2580 (8) | 0.2568 (7) | 0.2560 (7) | 0.2552 (8) |
z/c | 0.1116 (3) | 0.1120 (2) | 0.1140 (3) | 0.1134 (2) |
Beq(Å2) | 1.19 (5) | 1.17 (3) | 1.14 (2) | 1.22 (4) |
O6 | ||||
n | 1.01 (2) | 1.01 (2) | 1.02 (2) | 1.00 (2) |
x/a | 0.2172 (12) | 0.2111 (11) | 0.2092 (12) | 0.1862 (11) |
y/b | 0.2117 (8) | 0.2142 (7) | 0.2161 (7) | 0.2272 (8) |
z/c | 0.8747 (2) | 0.8760 (2) | 0.8782 (2) | 0.8791 (2) |
Beq(Å2) | 0.87 (5) | 0.87 (3) | 0.94 (2) | 0.82 (4) |
Rp | 5.23 | 5.51 | 5.54 | 5.33 |
Rwp | 6.86 | 7.06 | 7.12 | 7.01 |
RB
| 4.71 | 5.01 | 5.04 | 4.92 |
χ2
| 1.19 | 1.27 | 1.31 | 1.34 |
Cation | x = 0 | x = 0.4 | x = 0.6 | x = 0.8 |
---|---|---|---|---|
Bi1/Tb1 | ||||
O5 | 2.301 | 2.308 | 2.304 | 2.288 |
O3 | 2.402 | 2.355 | 2.353 | 2.334 |
O3 | 2.411 | 2.438 | 2.422 | 2.369 |
O6 | 2.519 | 2.470 | 2.454 | 2.469 |
O5 | 2.559 | 2.554 | 2.459 | 2.472 |
O1 | 2.659 | 2.560 | 2.584 | 2.562 |
O1 | 2.853 | 2.878 | 2.836 | 2.852 |
O6 | 2.904 | 2.922 | 2.836 | 2.858 |
O1 | 3.020 | 2.961 | 3.020 | 3.002 |
O3 | 3.072 | 3.039 | 3.067 | 3.029 |
O3 | 3.102 | 3.117 | 3.151 | 3.155 |
O1 | 3.189 | 3.279 | 3.378 | 3.352 |
Bi2/Tb2 | ||||
O2 | 2.179 | 2.183 | 2.205 | 2.206 |
O2 | 2.252 | 2.297 | 2.269 | 2.237 |
O2 | 2.329 | 2.318 | 2.355 | 2.282 |
O2 | 2.506 | 2.450 | 2.427 | 2.408 |
O4 | 2.555 | 2.583 | 2.592 | 2.587 |
O4 | 2.647 | 2.620 | 2.644 | 2.647 |
O4 | 3.156 | 3.163 | 3.204 | 3.171 |
O4 | 3.228 | 3.197 | 3.242 | 3.215 |
O6 | 3.289 | 3.309 | 3.354 | 3.327 |
Ti1 | ||||
O1X2 | 1.909 | 1.916 | 1.908 | 1.896 |
O3X2 | 1.950 | 1.955 | 1.982 | 1.978 |
O1X2 | 1.969 | 1.974 | 1.998 | 1.994 |
Ti2 | ||||
O4 | 1.766 | 1.729 | 1.692 | 1.684 |
O6 | 1.875 | 1.826 | 1.796 | 1.768 |
O5 | 2.000 | 1.997 | 1.959 | 1.960 |
O6 | 2.016 | 2.014 | 2.019 | 2.034 |
O5 | 2.024 | 2.072 | 2.115 | 2.139 |
O3 | 2.331 | 2.328 | 2.326 | 2.329 |
Cation | x | δ (Å) | ξ (Å) | V (Å3) | Δ | Valence |
---|---|---|---|---|---|---|
Bi1/Tb1 (c.n. = 12) | 0 | 0.042 | 2.749 ± 0.311 | 48.2 (1) | 0.072 | 2.88 |
0.4 | 0.057 | 2.740 ± 0.329 | 47.8 (1) | 0.068 | 2.86 | |
0.6 | 0.089 | 2.737 ± 0.355 | 47.6 (1) | 0.069 | 2.97 | |
0.8 | 0.091 | 2.729 ± 0.358 | 47.3 (1) | 0.067 | 3.06 | |
Bi2/Tb2 (c.n. = 9) | 0 | 0.419 | 2.682 ± 0.434 | 36.6 (1) | 0.098 | 2.93 |
0.4 | 0.416 | 2.680 ± 0.430 | 36.8 (1) | 0.096 | 2.91 | |
0.6 | 0.387 | 2.691 ± 0.449 | 37.2 (1) | 0.091 | 2.85 | |
0.8 | 0.379 | 2.687 ± 0.438 | 37.3 (1) | 0.088 | 2.91 | |
Ti1 (c.n. = 6) | 0 | 0.128 | 1.943 ± 0.027 | 9.6 (1) | 0.011 | 4.13 |
0.4 | 0.121 | 1.941 ± 0.027 | 9.7 (1) | 0.010 | 4.16 | |
0.6 | 0.098 | 1.963 ± 0.043 | 9.8 (1) | 0.016 | 4.04 | |
0.8 | 0.096 | 1.956 ± 0.047 | 9.8 (1) | 0.015 | 4.11 | |
Ti2 (c.n. = 6) | 0 | 0.037 | 1.984 ± 0.019 | 10.3 (1) | 0.013 | 3.94 |
0.4 | 0.051 | 1.995 ± 0.208 | 10.1 (1) | 0.016 | 4.13 | |
0.6 | 0.057 | 1.973 ± 0.246 | 9.7 (1) | 0.020 | 4.18 | |
0.8 | 0.061 | 1.979 ± 0.248 | 9.8 (1) | 0.021 | 4.16 |
3.2 IR spectroscopy
3.3 Second harmonic generation (SHG) response
3.4 Thermal analysis
3.5 Dielectric spectroscopy
3.6 Magnetic measurements
x | μeff/f.u. (μB) | θCW (K) | μcalc (μB) |
---|---|---|---|
0 | 0.53 | −1 | 0 |
0.4 | 5.63 | −2 | 6.15 |
0.6 | 7.35 | −4 | 7.53 |
0.8 | 8.09 | −3 | 8.69 |