Repozytorium

DSC, dilatometric, dielectric and 1H NMR studies of phase transition and molecular motions in [N(C2H5)4]3M2Cl9 (M = Sb, Bi) crystals.

Autorzy

J. Zaleski

Wojciech Medycki

N. Piślewski

Ryszard Jakubas

Rok wydania

1995

Czasopismo

Physica Status Solidi B-Basic Solid State Physics

Numer woluminu

190

Strony

199-210

DOI

10.1002/pssb.2221900128

Kolekcja

Naukowa

Język

Angielski

Typ publikacji

Artykuł

Streszczenie

Results in the dependence of stoichiometry of obtained tetraethylammonium (TEA) chloroantiomonatc and chlorobismuthate salts on the molar ratio of reactants used in the synthesis are presented. Seven tetraethylammonium salts are obtained: (TEA)6M8Cl30, TEAMCl4, (TEA)3M2Cl9 (M = Sb, Bi) and (TEA)2SbCl5. Preliminary X-ray diffraction studies on (TEA)3M2Cl9 (M = Sb, Bi) show that they are isomorphous, crystallizing at room temperature in monoclinic symmetry. The dilatometric, dielectric, and DSC studies show that (TEA)3Bi2Cl9 undergoes two phase transitions at Tc2 = 144K and at Tc1 = 322K while (TEA)3Sb2Cl9 undergoes three transitions at Tc3, = 185. Tc2 = 219, and Tc1 = 321 K. Both crystals are ferroelastic below the ferro-paraelastic transition at Tc1. The room temperature domain structure belongs to the Aizu species 6/mmmF2/m. The spin-lattice relaxation times and the values of the second moments of the 1 NMR line for the (TEA)3Sb2Cl9 crystal are measured in the temperature range of 50 to 350K. Three minima of T1 are observed. Two low-temperature minima are attributed to CH3 group reorientations, while the high-temperature one to reorientations of the whole cations. The activation energies for the processes are determined.

Adres publiczny

https://doi.org/10.1002/pssb.2221900128

Strona internetowa wydawcy

onlinelibrary.wiley.com

Podobne publikacje
1993

NMR and dilatometric studies on [N(CH3)4]3M2X9 (M=Sb, Bi; X=Cl, Br).

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