Nucleation and crystal formation in lithium disilicate‐apatite glass‐ceramic from a combined use of X‐ray diffraction, solid‐state NMR, and microscopy

Author(s):  
Christophe Copéret ◽  
Wei-Chih Liao ◽  
Markus Rampf ◽  
Marc Dittmer ◽  
Wolfram Höland
2002 ◽  
Vol 80 (8) ◽  
pp. 1162-1165 ◽  
Author(s):  
B Henrissat ◽  
G K Hamer ◽  
M G Taylor ◽  
R H Marchessault

A series of dodecyl 1-thio-β-D-glycosides has been synthesized and characterized (DSC, NMR, CP MAS, X-ray diffraction) as possible new marking materials with liquid-crystalline properties. These compounds undergo solid to liquid crystal phase transitions at various temperatures, which depend on the nature of the carbohydrate part of the structure. Their liquid-crystalline phases show extreme shear thinning behaviour.Key words: liquid crystal, powder X-ray diffraction, phase transition, thioglycoside, solid-state NMR, marking material


1997 ◽  
Vol 8 (6) ◽  
pp. 581-586 ◽  
Author(s):  
Alcides Wagner Serpa Guarino ◽  
Rosane A. S. San Gil ◽  
Helena Polivanov ◽  
Sonia M.C. Menezes

2017 ◽  
Vol 72 (8) ◽  
pp. 609-615
Author(s):  
Lukas Heletta ◽  
Stefan Seidel ◽  
Christopher Benndorf ◽  
Hellmut Eckert ◽  
Rainer Pöttgen

AbstractThe gallium-containing Heusler phases ScRh2Ga, ScPd2Ga, TmRh2Ga and LuRh2Ga have been synthesized by arc-melting of the elements followed by different annealing sequences to improve phase purity. The samples have been studied by powder X-ray diffraction. The structures of Lu0.97Rh2Ga1.03 (Fm3̅m, a=632.94(5) pm, wR2=0.0590, 46 F2 values, seven variables) and Sc0.88Rh2Ga1.12 (a=618.91(4) pm, wR2=0.0284, 44 F2 values, six variables) have been refined from single crystal X-ray diffractometer data. Both gallides show structural disorder through Lu/Ga and Sc/Ga mixing. Temperature dependent magnetic susceptibility measurements showed Pauli paramagnetism for ScRh2Ga, ScPd2Ga, and LuRh2Ga and Curie-Weiss paramagnetism for TmRh2Ga. 45Sc and 71Ga solid state MAS NMR spectroscopic investigations of the Sc containing compounds confirmed the site mixing effects typically observed for Heusler phases. The data indicate that the effect of mixed Sc/Ga occupancy is significantly stronger in ScRh2Ga than in ScPd2Ga.


2020 ◽  
Vol 302 ◽  
pp. 110197
Author(s):  
Takuji Ikeda ◽  
Yuka Yoshida ◽  
Naoto Nakazawa ◽  
Satoshi Inagaki ◽  
Yoshihiro Kubota

2019 ◽  
Vol 19 (3) ◽  
pp. 1860-1873 ◽  
Author(s):  
Inês C. B. Martins ◽  
Mariana Sardo ◽  
Edith Alig ◽  
Lothar Fink ◽  
Martin U. Schmidt ◽  
...  

2001 ◽  
Vol 691 ◽  
Author(s):  
Michael J. Ferguson ◽  
Igor L. Moudrakovski ◽  
Christopher I. Ratcliffe ◽  
John S. Tse

ABSTRACTThe Structure I type binary metal clathrates of K/Si, Rb/Si and Cs/Sn have been synthesised and studied by powder X-ray diffraction and solid state NMR. Rietveld analysis shows that in all three materials some of the cages are empty, and that in the Cs/Sn clathrate there are vacancies in the Sn framework. The NMR results yield Knight shifts for 29Si and 39K and confirm that the Cs/Sn clathrate is not conducting. Many of the features of the NMR spectra can be understood in terms of the distributions of atom vacancies.


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