Elastic neutron scattering in electric-field-biased deuterated betaine calcium chloride dihydrate

1992 ◽  
Vol 46 (5) ◽  
pp. 3098-3100 ◽  
Author(s):  
M. R. Chaves ◽  
A. Almeida ◽  
J. M. Kiat ◽  
W. Schwarz ◽  
J. Schneck ◽  
...  
Keyword(s):  
Electric Field ◽  
Neutron Scattering ◽  
Calcium Chloride ◽  
Elastic Neutron ◽  
Chloride Dihydrate ◽  
Elastic Neutron Scattering ◽  
Calcium Chloride Dihydrate

Dielectric constant in electric field biased deuterated betaine calcium chloride dihydrate

1993 ◽  
Vol 141 (1) ◽  
pp. 13-17 ◽  
Author(s):  
A. Almeida ◽  
M. R. Craves ◽  
J. L. Ribeiro ◽  
A. Klopperpieper ◽  
H. E. Muser ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Electric Field ◽  
Calcium Chloride ◽  
Chloride Dihydrate ◽  
Calcium Chloride Dihydrate

Structures of room-temperature and ferroelectric (35 K) phases of deuterated betaine calcium chloride dihydrate

1996 ◽  
Vol 52 (5) ◽  
pp. 810-816 ◽  
Author(s):  
J. M. Ezpeleta ◽  
F. J. Zúñiga ◽  
W. Paulus ◽  
A. Cousson ◽  
J. Hlinka ◽  
...  
Keyword(s):  
Calcium Chloride ◽  
Room Temperature ◽  
Incommensurate Phase ◽  
Elastic Neutron ◽  
Chloride Dihydrate ◽  
Modulated Phases ◽  
Structural Distortions ◽  
Different Temperatures ◽  
Calcium Chloride Dihydrate ◽  
Three Phases

The structures of the room-temperature and the lowest-temperature ferroelectric phases of fully deuterated betaine (trimethylammonioacetate) calcium chloride dihydrate have been determined by means of elastic neutron diffraction. In previous structural studies the structural distortions of the incommensurate phase at 130 K and the fourfold phase at 90 K were analyzed in terms of symmetry modes. The same approach has been applied in the present case and, as a result, a quantitative comparison of the distortions at different temperatures can be performed. This shows that the Λ 3 (for q ≠ 0) and B 2u (for q = 0) modes, corresponding to the order parameter, are predominant for the three phases. In addition, it has been found that the structure of this primary mode remains essentially unaltered in the three phases. There is only an increase in its global amplitude as the temperature decreases. Accordingly, it can be expected that the structures of the remaining intermediate modulated phases in the transition sequence are similar to that of the first incommensurate phase, except for the change of wavevector values and greater amplitude of the distortion. Crystal data: (CD3)3NCD2COOCaCl2.2D2O, Mr = 279.0, λ = 0.8308 Å, Z = 4, F(000) = 552. At room temperature: Pnma, a = 10.95 (1), b = 10.15 (1), c = 10.82 (1) Å, V = 1203 (2) Å3, Dx = 1.54 g cm−3, μ = 0.10 cm−1, final R = 0.048 for 748 unique observed reflections. At 35 K: Pn21 a, a = 10.905 (9), b = 10.00 (1), c = 10.80 (1) Å, V = 1178 (2) Å3, Dx = 1.57 g cm−3, μ = 0.11 cm−1, final R = 0.042 for 1726 unique observed reflections.

Membranes studied using neutron scattering and NMR

1995 ◽  
Vol 73 (11-12) ◽  
pp. 687-696 ◽  
Author(s):  
Myer Bloom ◽  
Thomas M. Bayerl
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Neutron Scattering ◽  
Spectral Characteristics ◽  
Nmr Relaxation ◽  
Elastic Neutron ◽  
Fluid Membranes ◽  
Dynamical Properties ◽  
Elastic Neutron Scattering ◽  
Complementary Techniques

After reviewing some of the basic measurements that characterize the study of physical properties of matter using neutron scattering and nuclear magnetic resonance (NMR), connections between information obtained in current research on fluid membranes using these two complementary techniques are explored in two major chapters. In the first, the type of information on the structure of fluid membranes obtained from coherent elastic neutron scattering is compared with that from NMR spectral characteristics. Then, the type of information obtained on dynamical properties from NMR relaxation (T1 and T2) measurements is compared with that from quasi-elastic neutron scattering. Examples of such connections are given with an emphasis on relationships between the time and distance scales intrinsic to neutron scattering and NMR.

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