Thermal decomposition of monocalcium aluminate decahydrate (CaAl2O4·10H2O) investigated by in-situsynchrotron X-ray powder diffraction, thermal analysis and27Al,2H MAS NMR spectroscopy

2008 ◽  
pp. 455-462 ◽  
Author(s):  
Axel Nørlund Christensen ◽  
Torben R. Jensen ◽  
Bente Lebech ◽  
Jonathan C. Hanson ◽  
Hans J. Jakobsen ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Thermal Decomposition ◽  
Nmr Spectroscopy ◽  
Powder Diffraction ◽  
Mas Nmr ◽  
X Ray

Obtaining aluminas from the thermal decomposition of their different precursors: An 27Al MAS NMR and X-ray powder diffraction studies

2014 ◽  
Vol 49 ◽  
pp. 216-222 ◽  
Author(s):  
L.H. Chagas ◽  
G.S.G. De Carvalho ◽  
R.A.S. San Gil ◽  
S.S.X. Chiaro ◽  
A.A. Leitão ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Powder Diffraction ◽  
Mas Nmr ◽  
X Ray ◽  
27Al Mas Nmr

Crystal structures and cation ordering in Cs2MgSi5O12, Rb2MgSi5O12 and Cs2ZnSi5O12 leucites

2009 ◽  
Vol 65 (4) ◽  
pp. 435-444 ◽  
Author(s):  
A. M. T. Bell ◽  
C. M. B. Henderson
Keyword(s):  
Nmr Spectroscopy ◽  
Crystal Structures ◽  
Powder Diffraction ◽  
Divalent Cation ◽  
Mas Nmr ◽  
Cation Ordering ◽  
X Ray ◽  
Tetrahedral Sites ◽  
Starting Model ◽  
Leucite Structure

The crystal structures of the leucite analogues Cs2MgSi5O12, Cs2ZnSi5O12 and Rb2MgSi5O12 have been determined by synchrotron X-ray powder diffraction using Rietveld refinement in conjunction with 29Si MAS NMR spectroscopy. These leucites are framework structures with distinct tetrahedral sites (T sites) occupied by Si and a divalent cation (either Mg or Zn in these samples); there is also a monovalent extra-framework cation (either Cs or Rb in these samples). The refined crystal structures were based on the Pbca leucite structure of Cs2CdSi5O12, thus a framework with five ordered Si T sites and one ordered Cd T site was used as the starting model for refinement. 29Si MAS NMR shows five distinct Si T sites for Cs2MgSi5O12 and Rb2MgSi5O12, but six Si T sites for Cs2ZnSi5O12. The refined structures for Cs2MgSi5O12 and Rb2MgSi5O12 were determined with complete T-site ordering, but the refined structure for Cs2ZnSi5O12 was determined with partial disorder of Mg and Si over two of the T sites.

Investigations on the Thermal Decomposition of Coordination Polymers Based on Copper(I) Halides and 2-Methylpyrazine

2001 ◽  
Vol 56 (10) ◽  
pp. 997-1002 ◽  
Author(s):  
Chnstian Näther ◽  
Inke Jeß ◽  
Harald Studzinski
Keyword(s):  
Thermal Analysis ◽  
Thermal Decomposition ◽  
Differential Thermal Analysis ◽  
Thermal Behaviour ◽  
Powder Diffraction ◽  
Coordination Polymers ◽  
Intermediate Phase ◽  
Compound I ◽  
X Ray

The thermal behaviour of the three coordination polymers 2∞poly[CuX(μ-2-methylpyrazine- N,N′)] (X = Cl (I), Br (II)), and 2∞poly[{Cu2l2 (μ-pyrazine-N,N′)2 } · 2-methylpyrazine] (III) was investigated using differential thermal analysis and thermogravimetry (DTA-TG) measurements as well as temperature resolved X-ray powder diffraction in argon and in air. On heating all compounds decompose in two steps. In the first step compound I and II loose one and compound III looses two of the 2-methylpyrazine ligands to form the corresponding 2:1 compounds Cu2Cl2(2 -methylpyrazine) (IV) and 2∞poly[Cu2X2 (μ-2 -methylpyrazine-N,N′)] (X = Br (V), I (VI)). From the experiments there is no evidence for the formation of a 1:1 compound of Cul and 2-methylpyrazine as an intermediate phase during the thermal decomposition. On further heating the 2:1 compounds IV, V and VI transform directly to the corresponding copper(I) halides.

Formation of iron-doped mullite (Al4+2xSi2−2xO10−x) by temperature- and time-resolved X-ray powder diffraction and EXAFS, and by 27Al MAS NMR spectroscopy

Polyhedron ◽  
1999 ◽  
Vol 18 (7) ◽  
pp. 1083-1087 ◽  
Author(s):  
Frank J Berry ◽  
Robert L Bilsborrow ◽  
Andrew J Dent ◽  
Michael Mortimer ◽  
Clive B Ponton ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Powder Diffraction ◽  
Mas Nmr ◽  
Time Resolved ◽  
X Ray ◽  
27Al Mas Nmr ◽  
Iron Doped
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