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We synthesized Nb x Mo 1-x O 2 series compounds and determined the structure of each component through x-ray diffraction and selected area electron diffraction techniques. For x=0.05, 0.1, 0.2, they possess room temperature MoO 2 monoclinic structure (P 2 1 / c); for x=0.25, 0.3, they become to body-centered tetragonal structure (I 4 1 / a); for x=0.33, 0.6, 0.65, they further turn to TiO 2 rutile-type structure (P 4 2 / mnm). Nb 0.25 Mo 0.75 O 2 has transport and magnetic properties similar to those of NbMoO 4 as paramagnetic metal. Moreover, the UV–vis spectra indicate the metallic property of Nb 0.05 Mo 0.95 O 2 , Nb 0.25 Mo 0.75 O 2 , and Nb 0.6 Mo 0.4 O 2. X-ray absorption spectra at the Mo-L 3 and Nb-L 3 edges present Mo4+/Nb4+ and Mo4+/Nb5+ valence state for Nb 0.25 Mo 0.75 O 2 and Nb 0.05 Mo 0.95 O 2 , respectively. This means the latter can be descripted as Nb 0.05 Mo 0.95 O 2+δ with δ = 0.025. We synthesized a series of compounds Nb x Mo 1-x O 2 and identified the different structures corresponding to various components through XRD analyses and SAED experiments. Furthermore, we conducted physical property studies on the compounds with different compositions. [Display omitted] • Successfully synthesized Nb x Mo 1-x O 2 , including unreported components. • Nb x Mo 1-x O 2 has diverse structures with different chemical contents. • Determining the transport properties of Nb x Mo 1-x O 2. [ABSTRACT FROM AUTHOR]

Studies the high-pressure and high-temperature synthesis of a single-phase sample of MgB[sub2]. Superconductivity of the compound; Usage of X-ray diffraction and Rietveld analysis; Identification of the structure of the sample.

ZnS nanotetrapods synthesized via a solvothermal route have a octahedral core with a zincblende (ZB) structure and four hexprism-shaped arms consisting of alternately stacking ZB and wurtzite (WZ) phases, where the WZ phase has a higher volume percentage.In situangular-dispersive X-ray diffraction (ADXRD) measurements were carried out to study the structural behavior of ZnS nanotetrapods under high pressure up to 41.3 GPa. The initial WZ structure exhibits a very high mechanical stability to ∼11.3 GPa. Both the WZ and ZB structures transform to the rocksalt (RS) structure at ∼15.4 GPa. The bulk moduli of the WZ (148.2 ± 8.9 GPa) and RS (165.6 ± 9.9 GPa) phases are both larger than the previously reported values. These phenomena are discussed based on the alternating epitaxial growth of the WZ and ZB phases in the arms of nanotetrapods. Our study suggests that the internal structure of nanomaterials could also greatly affect their stability and transition behavior. [ABSTRACT FROM PUBLISHER]

Abstract: Nanosintering behaviour of MgAl2O4 ultra-fine powder was investigated under high pressure. We found that the nanosintering mechanism under high pressure was quite different from that under ambient pressure. To shed light on the mechanism, the residual stress, grain size, and boundary situation were investigated using HRTEM and XRD, respectively. Our results show high pressure can restrain grain growth and initiate plastic deformation to eliminate pores and/or additional phases existing in triple junctions of the grains. However, the conventional sintering process is controlled by grain growth to avoid imperfections between grain boundaries when preparing transparent ceramics. [Copyright &y& Elsevier]

The perovskite-like structure compound Ca0.85CuO2 has interesting structural properties: it has infinite one-dimensional edge-sharing copper-oxygen chains as well as partial occupancy of the Ca sites resulting in an incommensurate superstructure. In situ high-pressure energy dispersive X-ray diffraction measurements on polycrystalline powder Ca0.85CuO2 have been performed by using diamond anvil cell (DAC) instrument with synchrotron radiation. The results for the first time show that edge-sharing copper oxide Ca0.85CuO2 undergoes a structural transition at 14.5 GPa, and furthermore the structural transition is reversible. [ABSTRACT FROM AUTHOR]

Reports on in situ high pressure energy dispersive X-ray diffraction measurements on cubic-perovskite superconductor MgCNi[sub 3] under pressure up to 22 GPa using diamond anvil cell with synchrotron radiation. Crystal structure and compressibility; Stability of the structure of the superconductor.