Proton dynamics in letovicite, (NH4)3H(SO4)2

A 1H and 14N NMR spectroscopic study

verfasst von
Michael Fechtelkord, Astrid Engelhardt, Josef Christian Buhl, Lutz Schwalowsky, Ulrich Bismayer
Abstract

The improper ferroelastic phase letovicite (NH4)3H(SO4)2 has been studied by 1H MAS NMR as well as by static 14N NMR experiments in the temperature range of 296-425 K. The 1H MAS NMR resonance from ammonium protons can be well distinguished from that of acidic protons. A third resonance appears just below the phase transition temperature which is due to the acidic protons in the paraelastic phase. The lowering of the second moment M2 for the ammonium protons takes place in the same temperature range as the formation of domain boundaries, while the signals of the acidic protons suffer a line narrowing in the area of Tc. The static 14N NMR spectra confirm the temperature of the motional changes of the ammonium tetrahedra. Two-dimensional 1H NOESY spectra indicate a chemical exchange between ammonium protons and the acidic protons of the paraphase.

Organisationseinheit(en)
Institut für Mineralogie
Externe Organisation(en)
Universität Hamburg
Typ
Artikel
Journal
Solid State Nuclear Magnetic Resonance
Band
17
Seiten
76-88
Anzahl der Seiten
13
ISSN
0926-2040
Publikationsdatum
02.2000
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Strahlung, Allgemeine Chemie, Kern- und Hochenergiephysik, Instrumentierung
Elektronische Version(en)
https://doi.org/10.1006/snmr.2000.0006 (Zugang: Geschlossen)