Neutron diffraction measurements

Figure 4 Comparison of average distances from the bilayer center along the bilayer normal for deuterated methyl and methylene groups distributed throughout the DPPC molecule computed from constant-pressure MD calculations and neutron diffraction measurements on gel and liquid crystalline phase DPPC bilayers.

In molten salts, for example, this assumption is supported by X-ray and neutron-diffraction measurements. See Levy and Danford4 for a discussion of this point. 

Indeed, the precise location of hydrogen atoms by means of microwave spectroscopy involves the study of a complete set of isotopic (deuterated) derivatives, which is often costly and time-consuming. An alternative method, based on neutron diffraction measurements, is difficult to carry out for many obvious reasons. 

Later on, the role of each effect was examined more precisely by high-pressure neutron diffraction measurements on KDP and DKDP [13,14]. The linear relationship between Tc and Rq-q was confirmed in both KDP and DKDP for Tc > 50 K and the same slope dTc/dJ o-o was found in both crystals. However, the line in DKDP was found to be shifted from the line in KDP by about 40 K toward higher values. This result indicates that only part of 40 K 37%) of the whole isotope effect - Tf = 107 K) is caused by... 

Curry, N.A. Johnston, G.B. Besser, P.J. Mor-rish, A.H. (1965) Neutron diffraction measurements on pure and doped synthetic hematite crystals. Phil. Mag. 12 221-228 Da Costa, A.C.S. Bigham, J.M. Rhoton, F.E. Traina, S.J. (1999) Quantification and characterization of maghemite in soils derived from volcanic rocks in Southern Brazil. Clays Clay Min. 47 466-473... 

Most of the devices presented in this discussion could be used in both X-ray or neutron diffraction experiments, though taking into account that neutron diffraction measurements are typically longer and carried out on larger samples. 

In a non-stoichiometric oxide of the type Mi jO (where M is a metal), the association of the vacancy and the positive hole, or M + ion, can form the simplest cluster complex for Fei , 0. X-ray and neutron diffraction measurements (Roth 1960) suggested that some Fe + ions are in tetrahedral sites (flgure 1.11(a)). An... 

Takahashi, S., Suzuya, K., Kohara, S., Koura, N., Curtiss, L.A., and Saboungi, M.-L., Structure of l-ethyl-3-methylimidazolium chloroaluminates Neutron diffraction measurements and ab initio calculations, Z. Phys. Chem., 209, 209-221, 1999. 

The structure of the K azide mol has been studied by Frevel (Ref 23) and others who have obtd diffraction data (Ref 36), neutron diffraction measurements (Ref 40) and its mol refraction (Ref 43)... 

The best, and longest known, case is that of the bifluoride anion in NaHF2 and KHF2. In each the FHF ion lies across a centre of symmetry, and careful neutron-diffraction study finds the proton at the centre. However, neutron diffraction also shows, or appears to show, that the proton vibrates with a particularly large amplitude along the F H F bond. So there is a possibility that this may be partly due to disorder — qualitatively like that in ice (see also section 12), but now with the alternative proton sites not more than 0.1 A from the centre. The neutron-diffraction measurements can be equally well explained by two models the proton vibrates... 

More recently Choi Prince (Ref 55) used neutron diffraction measurement to determine that RDX crystallizes in the orthorhombic space... 

Hester and Sloan (2005) extended the size-structure correlations for double hydrates. A simple scheme of guest size-structure boundaries was proposed to predict the sl/sll structural transitions for double hydrates consisting of si hydrate formers (Figure 2.16). Raman spectroscopy and neutron diffraction measurements were performed to test the limits of these structural transitions. 

Todd, R.I., Morsi, K. and Derby, B. Neutron diffraction measurements of thermal residual microstresses in ceramic particle reinforced alumina , Brit. Ceram. Proc. 57 (1997) 87-101. 

Todd, R.I., Bourke, M.A.M., Borsa, C.E. and Brook, R.J. Neutron diffraction measurements of residual stresses in alumina/SiC nanocomposites , Acta Mater. 45 (1997) 1791-1800. 

Selected Bond Distances (A) and Angles ( ) within the KCsHslFeiCOLL Complex Given by Neutron Diffraction Measurement"... 

Comparison of the spectroscopic data on Er2BaNi05 [6, 8] with the results of neutron diffraction measurements [9] shows that the ground-doublet splitting... 

Andr6 et al. (2000) reported results of neutron diffraction measurements performed on ZfAgSb2 (R = Ce, Pr, Nd, Tb, Dy, Ho, Er, Tm). All compounds were found to be collinear antiferromagnets with the Neel temperature between 2.0 K (for TmAgSb2) and 11.1 K (for... 

Neutron diffraction measurements of stoichiometric composition [11, 18] revealed that the magnetic moment is localized mainly on Mn atoms. Reported values of the Mn magnetic moment range from 3.8 to 4.2 pb-The magnetic moment of Ni atoms is considerably smaller, about 0.2 — 0.4 fj,B- Compositional dependence of the magnetic moment in Ni2+a Mni xGa alloys has not been reported. It is known only that the magnetization saturation decreases with increasing x [19, 20],... 

This isomorphic substitution technique has also been used for neutron diffraction measurements as an attempt to extend the use of difference methods beyond what can be obtained by isotopic substitution (22). The structures of the aqua ions of Mn(II) and Cu(II), using Ni(II) as the isomorph, have been investigated in this way (Table II). 

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