Browsing by Author "Fei, Y"

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    Direct observation of nano-polar-domain phase transition in PLZT ceramics by SANS
    (The Bragg Institute, Australian Nuclear Science and Technology Organisation, 2005-11-27) Fei, Y; Piltz, RO; Choy, CL; Lou, HS; Xi, TG; Strunz, P
    Small Angle Neutron Scattering (SANS) measurements on Pb(0.92) La(0.08) Zr(0.60) Ti(0.40) O3 (PLZT) ceramics reveals that the ferroelectric phase experiences the evolution into nano-polar-domain (NPD) around the ferroelectric phase transition temperature Tc. This NPD gradually diminished as the temperature increased above the Tc. This director observation gives a strong support on the theory of nanometer-sized polar regions responsible for the extra larger ferroelectric and dielectric constant in this system. © The Authors
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    In situ neutron-diffraction study of the Ti38V30Cr14Mn18 structure during hydrogenation
    (Elsevier Science BV, 2013-11-01) Fei, Y; Kong, X; Wu, Z; Li, HH; Peterson, VK
    The phase transformations of the Ti38V30Cr14Mn18 alloy during hydrogenation and dehydrogenation using deuterium (D2) were investigated using in situ neutron powder diffraction (NPD) at various D2 pressures up to 2 MPa. Initially, the first hydride that formed, Ti38V30Cr14Mn18D15, had the same body centered cubic (BCC) crystal structure as the starting alloy. Upon further hydrogenation, the system displays a distinct two-phase mixture of the intermediate BCC and body-centered tetragonal (BCT) phases, that exist in a ration of 1.38:1.42, respectively. At the end of the deuterium absorption, the phase pure Ti38V30Cr14Mn18D183 material forms, with a face-centered cubic (FCC) structure. Upon dehydrogenation, all hydride phases eventually returned to the initial alloy phase without any amorphization or disproportionation. Using standard Rietveld refinement, information on the variation of the deuterium site occupancy, the lattice symmetry, and the cell volume were determined during these phase changes and are presented. © 2013, Elsevier Ltd.
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    Online reduction and analysis in GumTree
    (The Bragg Institute, Australian Nuclear Science and Technology Organisation, 2005-11-27) Rayner, H; Franceschini, F; Lam, T; Fei, Y
    This paper discusses how ANSTO aims to improve the experience of its neutron beam instrument users by integrating data reduction tools with the instrument control interface. The expectation is that the users will be able to make informed decisions to guide their experiments thus helping them improve the quality of their data via an interactive process with instant feedback. GumTree is an Integrated Scientific Experimental Environment. Data Reduction and Analysis (DRA) is a component of the GumTree Framework that allows users to perform data reduction, correction and basic analysis within GumTree while an experiment is running. It is highly integrated with Gumtree, able to pull data and metadata directly from the instrument control and data acquisition components. By having the DRA easily accessible while an experiment is running, the user will be able to make informed decisions concerning the running of the experiment. The DRA uses common components over all instruments and so provides a consistent interface. It utilises ISAW-based one and two dimensional plotting and an OpenGL-based three dimensional plotter. Peak fitting is performed by fityk. The paper will cover the benefits of integration, the flexibility of the DRA, intuitiveness of the interface and audit trail generation. © 2005 The Authors