Single-crystal neutron diffraction of urea-phosphoric acid: evidence for H-atom migration in a short hydrogen bond between 150 K and 350 K

2001 ◽  
Vol 216 (6) ◽  
Author(s):  
C. C. Wilson ◽  
K. Shankland ◽  
N. Shankland
Keyword(s):  
Hydrogen Bond ◽  
Neutron Diffraction ◽  
Phosphoric Acid ◽  
Single Crystal ◽  
Diffraction Data ◽  
Neutron Diffraction Data ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Short Hydrogen Bond ◽  
Atom Migration

AbstractThe structure of urea-phosphoric acid has been refined using single-crystal neutron diffraction data collected at seven temperatures in the range 150 K to 350 K. The structure is orthorhombic, space group

Migration of the proton in the strong O—H...O hydrogen bond in urea–phosphoric acid (1/1)

2001 ◽  
Vol 57 (3) ◽  
pp. 435-439 ◽  
Author(s):  
Chick C. Wilson
Keyword(s):  
Hydrogen Bond ◽  
Data Collection ◽  
Neutron Diffraction ◽  
Phosphoric Acid ◽  
Diffraction Data ◽  
Accurate Determination ◽  
Neutron Diffraction Data ◽  
Crystal Data ◽  
Collection Method

The structure of urea–phosphoric acid is reported at a large number of temperatures in the range 150–335 K from neutron diffraction data collected using a novel multiple single-crystal data collection method. The work focuses on the behaviour of the H atom involved in the short strong O—H...O hydrogen bond in this material. The position of this atom is shown to vary significantly, by around 0.035  Å, as a function of temperature, becoming effectively centred at the highest temperatures studied. This result, only accessible due to the accurate determination of H-atom parameters by neutron diffraction, has implications for the potential governing the hydrogen bond.

Crystal Data for Pb7Bi3, a Superconducting ε-Phase in the Pb-Bi System

1987 ◽  
Vol 2 (1) ◽  
pp. 28-28 ◽  
Author(s):  
Svend Erik Rasmussen ◽  
Britta Lundtoft
Keyword(s):  
Neutron Diffraction ◽  
Single Crystal ◽  
Diffraction Data ◽  
Superconducting State ◽  
Neutron Diffraction Data ◽  
Crystal Data ◽  
Space Group ◽  
X Ray ◽  
Crystal Material ◽  
Ε Phase

AbstractThe ε-phase is hexagonal, space group P63/mmc. For the composition Pb7Bi3 the following data were determined, a = 3.5058(1) Å c = 5.7959(5) Å, Vol. = 61.687 Å3(5), Dc = 11.17 Mg m−3. Filings from single crystal material were used to obtain powder data by the Guinier method and the X-ray results were in accordance with single crystal neutron diffraction data. Transition to the superconducting state took place in the interval 8.3 K–8.55 K.

The structure of perdeuteronaphthalene C10D8 at 12 K by neutron diffraction

1983 ◽  
Vol 163 (3-4) ◽  
Author(s):  
I. Natkaniec ◽  
A. V. Belushkin ◽  
W. Dyck ◽  
H. Fuess ◽  
C. M. E. Zeyen
Keyword(s):  
Crystal Structure ◽  
Neutron Diffraction ◽  
Diffraction Data ◽  
Molecular And Crystal Structure ◽  
Monoclinic Space Group ◽  
Neutron Diffraction Data ◽  
Space Group

AbstractThe molecular and crystal structure of perdeuteronaphthalene was refined from neutron diffraction data collected at 12 K on an automatic four-circle diffractometer. The monoclinic space group

Structure of Ce2Pt6Ga15: interplanar disorder from the Ce2Ga3 layers

1996 ◽  
Vol 52 (4) ◽  
pp. 580-585 ◽  
Author(s):  
G. H. Kwei ◽  
A. C. Lawson ◽  
A. C. Larson ◽  
B. Morosin ◽  
E. M. Larson ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Single Crystal ◽  
Diffraction Data ◽  
Diffuse Scattering ◽  
Heavy Fermion ◽  
Neutron Diffraction Data ◽  
Crystal Data ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
A Cell

The structure of the heavy fermion compound Ce2Pt6Ga15 has been determined from neutron powder and X-ray/neutron single-crystal diffraction. Examination of symmetry equivalence among the single-crystal data, as well as the good fit of the powder data to the final structural arrangement, with all the atoms on symmetry sites, suggests that the correct space group is P63/mmc. The structure is unusual in that Ce layers have 1/3 of the Ce atoms replaced by groups of three Ga atoms; distances between atoms in these planes suggest this substitution must occur in a concerted fashion. The refined occupancies lead to a stoichiometry near Ce2Pt6Ga15, consistent with such an arrangement. In addition, single-crystal neutron diffraction data show columns of weak diffuse scattering along the <001> axes, suggesting disorder arising from a lack of registration of successive Ce2Ga3 layers (lying half a cell length or 8.27 Å apart along z) and a 3 × 3 × 1 supercell. This disorder is very likely responsible for the low resistance ratio of approximately unity measured for single-crystal samples.

Structural and Magnetic Properties of La0.7Sr0.3Mn1-xNixO3 (x=0.05, 0.1, 0.2, 0.3, 0.4)

2011 ◽  
Vol 1327 ◽  
Author(s):  
Thomas F. Creel ◽  
Jinbo B. Yang ◽  
Mehmet Kahveci ◽  
Jagat Lamsal ◽  
Satish K. Malik ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Neutron Diffraction ◽  
Diffraction Data ◽  
Magnetic Measurements ◽  
Magnetic Ordering ◽  
Neutron Diffraction Data ◽  
Space Group ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Structural And Magnetic Properties

ABSTRACTWe have studied the structural and magnetic properties of La0.7Sr0.3Mn1-xNixO3 (x=0.05, 0.10, 0.20, 0.30, and 0.40) perovskites using x-ray and neutron diffraction and magnetic measurements. To our knowledge, there exists no neutron diffraction data available for this group of perovskite compositions. Neutron (λ = 1.479Å) and x-ray (λ = 1.5481Å; Cu Kα) powder diffraction indicate that for x ≥ 0.1 all samples are two-phase with a rhombohedral perovskite structure (space group R-3c) and a small amount of NiO (space group Fm3m). Neutron diffraction data for the perovskite phase at 12K and 300K show ferromagnetic ordering for x ≤ 0.2 and antiferromagnetic ordering for x = 0.4. However, for x = 0.3, neutron diffraction data at 12K show coexisting ferromagnetic and antiferromagnetic ordering while at 300K no magnetic ordering is found. Magnetic measurements indicate that the Curie temperature decreases with increasing Ni content. The NiO phase for all samples was found to have antiferromagnetic ordering at 12K and 300K. The magnetic measurements are consistent with the neutron diffraction data and together indicate long-range magnetic ordering for samples at low temperature and transitions from ferromagnetic to paramagnetic to antiferromagnetic ordering for samples at room temperature.

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