Incommensurately modulated crystal structure of α' (O'3)-type sodium cobalt oxide NaCoO (x ∼ 0.78).

A single-phase sample of α' (O'3)-type layered sodium cobalt oxide NaCoO (x ∼ 0.78) was prepared and its incommensurately modulated crystal structure was analyzed using the (3+1)-dimensional superspace approach to the powder neutron diffraction data. The crystal structure of the cobaltate is accurately described based on the superspace group C2/m(α0γ)00, wherein the positions of Na atoms are most significantly modulated in the monoclinic a direction to form an ordered arrangement.

Crystal Structures and Magnetic Properties of Nickel Chain Compounds PbM2Ni6Te3O18 (M = Mn, Cd).

The synthesis, crystal structures, and magnetic properties of the pentanary oxides PbM2Ni6Te3O18 (M = Mn and Cd) were investigated. These compounds crystallize in a hexagonal structure with space group P63/m, in which the Ni(2+) ions form a zigzag chain along the c axis. From the magnetic susceptibility and specific heat measurements, we found that the PbCd2Ni6Te3O18 behaves as a low-dimensional magnet due to the intrachain antiferromagnetic interaction between Ni(2+) ions.

Crystal and magnetic structures and properties of BiMnO(3+delta).

Crystal and magnetic structures of BiMnO(3+delta) (delta = 0.03, 0.08, and 0.

Simultaneous separation of anionic, cationic, and neutral components in capillary liquid chromatography using mixed-bed column of hydrophilic and anion-exchange stationary phases.

A simultaneous separation of anionic, cationic, and neutral compounds was carried out in capillary LC using a mixed-bed column of zwitterionic hydrophilic and anion-exchange stationary phases. The combination in stationary phases was suitable to retain anionic, cationic, and neutral analytes. The retentions of anionic compounds were suppressed with the increase in the buffer concentration in the mobile phase whereas those for the cationic and neutral compounds were almost constant, i.

Origin of the monoclinic-to-monoclinic phase transition and evidence for the centrosymmetric crystal structure of BiMnO3.

Structural properties of polycrystalline single-phased BiMnO3 samples prepared at 6 GPa and 1383 K have been studied by selected area electron diffraction (SAED), convergent beam electron diffraction (CBED), and the Rietveld method using neutron diffraction data measured at 300 and 550 K. The SAED and CBED data showed that BiMnO3 crystallizes in the centrosymmetric space group C2/c at 300 K. The crystallographic data are a = 9.

Observation of hydrogen in deuterated methane hydrate by maximum entropy method with neutron powder diffraction.

The crystal structure of deuterated methane hydrate (structure I, space group: Pm(-)3n) was investigated by neutron powder diffraction at temperatures of 7.7-185 K. The scattering amplitude density distribution was examined by a combination of Rietveld method and maximum entropy method (MEM).

BiScO3: centrosymmetric BiMnO3-type oxide.

With neutron powder diffraction, electron diffraction, and second-harmonic generation, we have shown that BiScO3 has a structure closely related to that of multiferroic BiMnO3, but BiScO3 crystallizes in the centrosymmetric space group of C2/c. These results bring up a question about the origin of ferroelectricity in BiMnO3. BiScO3 may serve as a model system to understand the role of Mn3+ ions in the ferroelectricity of BiMnO3.