Table 1 Crystallographic data of the as-prepared (orthorhombic phase) and post-annealed (tetragonal phase) La3Ni1.6Al0.4O7−δ from neutron powder diffractions
From: Stabilization of Tetragonal Phase and Aluminum-Doping Effect in a Bilayer Nickelate
Orthorhombic phase | La3Ni1.6Al0.4O6.90 |
|---|---|
Space group | Amam (No. 63) |
a (Å) | 5.4055(1) |
b (Å) | 5.4438(1) |
c (Å) | 20.4515(5) |
Rwp (%) | 6.18 |
S | 1.65 |
Atom | site | x | y | z | occ. | Uiso |
|---|---|---|---|---|---|---|
La(1) | 4c | 0.25 | 0.240(2) | 0.5 | 1.00 | 0.009(1) |
La(2) | 8g | 0.25 | 0.243(2) | 0.3191(1) | 1.00 | 0.009(1) |
Ni/Al | 8g | 0.25 | 0.247(2) | 0.0960(2) | 0.80/0.20 | 0.003(1) |
O(1) | 4c | 0.25 | 0.208(2) | 0 | 0.90(2) | 0.002(3) |
O(2) | 8g | 0.25 | 0.283(1) | 0.2015(3) | 1.00 | 0.010(1) |
O(3) | 8e | 0.5 | 0 | 0.1049(3) | 1.00 | 0.015(2) |
O(4) | 8e | 0 | 0.5 | 0.0901(3) | 1.00 | 0.001(2) |
Tetragonal phase | La3Ni1.6Al0.4O6.98 |
|---|---|
Space group | I4/mmm (No. 139) |
a (Å) | 3.83466(6) |
c (Å) | 20.4648(5) |
Rwp (%) | 7.83 |
S | 2.08 |
Atom | site | x | y | z | occ. | Uiso |
|---|---|---|---|---|---|---|
La(1) | 4e | 0 | 0 | 0.3184(2) | 1.00 | 0.009(1) |
La(2) | 2b | 0 | 0 | 0.5 | 1.00 | 0.009(1) |
Ni/Al | 4e | 0 | 0 | 0.0960(2) | 0.80/0.20 | 0.010(1) |
O(1) | 2a | 0 | 0 | 0 | 0.98(3) | 0.041(4) |
O(2) | 4e | 0 | 0 | 0.2022(3) | 1.00 | 0.025(1) |
O(3) | 8g | 0 | 0.5 | 0.0950(2) | 1.00 | 0.017(1) |
