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2 D NMR Study near the Ferroelectric Phase Transition of TSCC
Author(s) -
Engelke F.,
Michel D.,
Windsch W.,
Petersson J.
Publication year - 1987
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221390226
Subject(s) - ferroelectricity , deuterium , phase transition , crystallography , deuterium nmr , chemistry , nmr spectra database , nuclear magnetic resonance , electric field gradient , hydrogen bond , nuclear magnetic resonance spectroscopy , molecule , spectral line , materials science , dielectric , condensed matter physics , electric field , stereochemistry , atomic physics , physics , optoelectronics , organic chemistry , quantum mechanics , astronomy
Deuterium nuclear magnetic resonance ( 2 D NMR) investigations are performed in order to get information about structural changes of the hydrogen bonds for deuterated crystals of trissarcosine calcium chloride (TSCC) near the ferroelectric phase transition at T c = 130 K. The electric field gradient (efg) tensors at the deuterium sites in the hydrogen bonds are determined at room temperature by measuring the angular dependence of the spectra for rotations around the three crystallographic axes. Near the phase transition ( T c − T = 5 K) the positions of the 2 D NMR lines change in an interval of about 10 kHz. These changes can be explained through a rotation of the efg tensor by an angle of about 4° at 125 K. The interpretation is in agreement with results from 1 H ENDOR and 13 C ENDOR measurements of TSCC crystals doped with Mn 2+ according to which a static rotation of sarcosine molecules occurs at the phase transition giving rise also to the spontaneous polarization.