Abstract
The crystal structures of n = 3 Dion-Jacobson phases MLa2Ti2TaO10 (M = Cs, Rb) and NaLa2Ti2TaO10 · xH2O (x = 2, 0.9, 0) have been investigated by the Rietveld analysis of their powder XRD patterns. These compounds show the new-type ordering sequence of (Ti1/2 Ta1/2) O6-TiO6-(Ti1/2Ta1/2)O6 in the tripled octahedra, corresponding to the niobium analogs of MLa2Ti2NbO10. They crystallize in the tetragonal system P4/mmm with lattice constants of a = 3.84733(9) and c = 15.4364(4) Å for CsLa2Ti2TaO10, and a = 3.8342(2) and c = 15.2776(9) Å for RbLa2Ti2TaO10. Sodium-exchanged phase was easily hydrated to NaLa2Ti2TaO10 · 2H2O, belonging to the space group I4/mmm with a = 3.8399(3) and c = 34.288(3) Å. Upon firing, NaLa2Ti2TaO10 · 2H2O was dehydrated to NaLa2Ti2TaO10 · 0.9H2O with P4/mmm at around 100°C and then NaLa2Ti2TaO10 with I4/mmm at above 200°C. The Na cations in two hydrates were surrounded with six oxygens, forming face-shared octahedra along (110) direction. These structural models, especially for the coordination environment of Na cations, were proposed for the first time.
| Original language | English |
|---|---|
| Pages (from-to) | 290-298 |
| Number of pages | 9 |
| Journal | Journal of Solid State Chemistry |
| Volume | 158 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 2001 Oct 10 |
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Keywords
- Dion-Jacobson phase
- Hydrate
- Layered perovskite
- Ordering
ASJC Scopus subject areas
- Inorganic Chemistry
- Physical and Theoretical Chemistry
- Materials Chemistry
Cite this
Structural characterization of new layered perovskites MLa2Ti2TaO10 (M = Cs, Rb) and NaLa2Ti2TaO10 · xH2O (x = 2, 0.9, 0). / Hong, Young Sik; Han, Chi Hwan; Kim, Keon.
In: Journal of Solid State Chemistry, Vol. 158, No. 2, 10.10.2001, p. 290-298.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Structural characterization of new layered perovskites MLa2Ti2TaO10 (M = Cs, Rb) and NaLa2Ti2TaO10 · xH2O (x = 2, 0.9, 0)
AU - Hong, Young Sik
AU - Han, Chi Hwan
AU - Kim, Keon
PY - 2001/10/10
Y1 - 2001/10/10
N2 - The crystal structures of n = 3 Dion-Jacobson phases MLa2Ti2TaO10 (M = Cs, Rb) and NaLa2Ti2TaO10 · xH2O (x = 2, 0.9, 0) have been investigated by the Rietveld analysis of their powder XRD patterns. These compounds show the new-type ordering sequence of (Ti1/2 Ta1/2) O6-TiO6-(Ti1/2Ta1/2)O6 in the tripled octahedra, corresponding to the niobium analogs of MLa2Ti2NbO10. They crystallize in the tetragonal system P4/mmm with lattice constants of a = 3.84733(9) and c = 15.4364(4) Å for CsLa2Ti2TaO10, and a = 3.8342(2) and c = 15.2776(9) Å for RbLa2Ti2TaO10. Sodium-exchanged phase was easily hydrated to NaLa2Ti2TaO10 · 2H2O, belonging to the space group I4/mmm with a = 3.8399(3) and c = 34.288(3) Å. Upon firing, NaLa2Ti2TaO10 · 2H2O was dehydrated to NaLa2Ti2TaO10 · 0.9H2O with P4/mmm at around 100°C and then NaLa2Ti2TaO10 with I4/mmm at above 200°C. The Na cations in two hydrates were surrounded with six oxygens, forming face-shared octahedra along (110) direction. These structural models, especially for the coordination environment of Na cations, were proposed for the first time.
AB - The crystal structures of n = 3 Dion-Jacobson phases MLa2Ti2TaO10 (M = Cs, Rb) and NaLa2Ti2TaO10 · xH2O (x = 2, 0.9, 0) have been investigated by the Rietveld analysis of their powder XRD patterns. These compounds show the new-type ordering sequence of (Ti1/2 Ta1/2) O6-TiO6-(Ti1/2Ta1/2)O6 in the tripled octahedra, corresponding to the niobium analogs of MLa2Ti2NbO10. They crystallize in the tetragonal system P4/mmm with lattice constants of a = 3.84733(9) and c = 15.4364(4) Å for CsLa2Ti2TaO10, and a = 3.8342(2) and c = 15.2776(9) Å for RbLa2Ti2TaO10. Sodium-exchanged phase was easily hydrated to NaLa2Ti2TaO10 · 2H2O, belonging to the space group I4/mmm with a = 3.8399(3) and c = 34.288(3) Å. Upon firing, NaLa2Ti2TaO10 · 2H2O was dehydrated to NaLa2Ti2TaO10 · 0.9H2O with P4/mmm at around 100°C and then NaLa2Ti2TaO10 with I4/mmm at above 200°C. The Na cations in two hydrates were surrounded with six oxygens, forming face-shared octahedra along (110) direction. These structural models, especially for the coordination environment of Na cations, were proposed for the first time.
KW - Dion-Jacobson phase
KW - Hydrate
KW - Layered perovskite
KW - Ordering
UR - http://www.scopus.com/inward/record.url?scp=0034811937&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034811937&partnerID=8YFLogxK
U2 - 10.1006/jssc.2001.9109
DO - 10.1006/jssc.2001.9109
M3 - Article
AN - SCOPUS:0034811937
VL - 158
SP - 290
EP - 298
JO - Journal of Solid State Chemistry
JF - Journal of Solid State Chemistry
SN - 0022-4596
IS - 2
ER -