Search results for "Electron backscatter diffraction"
showing 10 items of 44 documents
Structure characterization of hard materials by precession electron diffraction and automatic diffraction tomography: 6H-SiC semiconductor and Ni1+xT…
2012
Using a combination of automated diffraction tomography and precession electron diffraction techniques, quasi-kinematical electron diffraction data sets were collected from intermetallic Ni1+xTe1 embedded nanodomains and ion-thinned specimens of 6H–SiC semiconductor. Cell parameters and space groups were found automatically from the reconstructed 3D diffraction volume. The extracted intensities were used for fast ab initio structure determination by direct methods.
Influence of the microstructure on the corrosion behaviour of low-carbon martensitic stainless steel after tempering treatment
2014
Abstract The microstructure of grade X4CrNiMo16.5.1 stainless steel was studied at different scales. The chemical composition of the native passive film formed on the different phases was then determined at the microscale. The degree of homogeneity of the native passive film is discussed. Subsequently, the susceptibility to pitting corrosion of X4CrNiMo16.5.1 was quantified using the electrochemical microcell technique. The nature of precursor sites and the morphology of pits were investigated by combining scanning electron microscopy with Electron BackScatter Diffraction and potentiostatic pulse tests. The role of the microstructure and the cold-worked layer generated by polishing in pitti…
Corrosion behaviour of heavily deformed pearlitic and brass-coated pearlitic steels in sodium chloride solutions
2014
Abstract The influence of plastic deformation and galvanic coupling on the microstructure and corrosion behaviour of pearlitic steel and brass-coated pearlitic steel was investigated in sodium chloride solution at 25 °C. Microstructural changes were quantified using scanning electron microscopy coupled with EBSD. Chemical and electrochemical modifications were evaluated using XPS, ZRA, the electrochemical microcell technique and the weight loss method. From these experiments, the influence of microstructural changes on the electrochemical parameters and the corrosion rate was discussed.
Neutron powder diffraction study in the mixed molecular system (NaCN)1−x(KCN)x
1989
A detailed structural analysis of (NaCN${)}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$(KCN${)}_{\mathrm{x}}$ mixed crystals with x=0.02, 0.19, and 0.95 was performed by neutron powder diffraction. The structural parameters of the cubic phases were refined, applying a model of preferred orientations. Different noncubic low-temperature phases were observed for x=0.02 and 0.95. For x=0.02 the antiferroelectric ordering of ${\mathrm{CN}}^{\mathrm{\ensuremath{-}}}$ dipoles at low temperatures is accompanied by significant alkali-alkali and alkali-${\mathrm{CN}}^{\mathrm{\ensuremath{-}}}$ sublattice shifts. Structural data are presented together with previous results for mixed crystals with x=0.59 and…
On the metal distribution in the system GeTe−Sb2Te3
1988
The structures of GeSb2Te4, Ge2Sb2Te5 and GeSb4Te7 are not determined completely by means of classical X-ray or electron diffraction studies. We have measured the Mossbauer parameters of121Sb in these compounds as well as in their binary constituent Sb2Te3 as an attempt to improve our knowledge on the question.
Structural modulations and phase transitions in β-eucryptite: an in-situ TEM study
1999
Beta-eucryptite as grown by the flux method has been investigated by in-situ cold- and hot-stage transmission electron microscopy (TEM). Using electron diffraction and dark-field TEM imaging, we found no evidence for the merohedral twinning that accompanies structural collapse at the β-to-α-quartz transition, suggesting a true hexagonal symmetry for the aluminosilicate framework of β-eucryptite. Selected-area electron diffraction (SAED) patterns exhibited a variety of incommensurate structures along the three a axes with an average modulation period of about 6.5 a. These modulated structures arise from superperiodic stacking parallel to (100) of two structural units with different Li config…
X-ray powder diffraction pattern for glucopyranosylsorbitol and glucopyranosylmannitol dihydrate
1997
X-ray powder data are given for glucopyranosylsorbitol, C12H24O11, and glucopyranosylmannitol dihydrate, C12H24O11 * 2H2O. Refined unit cell parameters for glucopyranosylsorbitol are: a=0.9124(4) nm, b=1.1336(5) nm, c=0.7232(3) nm, and β=91.23(4)° in space group P21 and those for glucopyranosylmannitol dihydrate are a=2.2579(15) nm, b=1.0016(5) nm, and c=0.7584(5) nm in space group P212121.
Accurate and precise lattice parameters by selected-area electron diffraction in the transmission electron microscope
2009
8 páginas, 6 figuras, 7 tablas.
Electron Diffraction Reinvestigation of CdCr<sub>2</sub>Se<sub>4</sub> and ZnCr<sub>2-x</sub>V<sub>x</su…
2013
Crystal structure of two spinel single crystals CdCr2Se4 and ZnCr2-xVxSe4 have been reinvestigated using automated electron diffraction tomography method with beam precession. 3D reciprocal space have been reconstructed base on recorded tilt series. For both samples crystal structure was refined and the cubic symmetry with space group Fd-3m was confirmed. No additional electron potential has been located beside occupied atom sites.
Microstructural, chemical and textural records during growth of snowball garnet
2009
The growth history of two populations of snowball garnet from the Lukmanier Pass area (central Swiss Alps) was examined through a detailed analysis of three-dimensional geometry, chemical zoning and crystallographic orientation. The first population, collected in the hinge of a chevron-type fold, shows an apparent rotation of 360 degrees. The first 270 degrees are characterized by spiral-shaped inclusion trails, gradual and concentric Mn zoning and a single crystallographic orientation, whereas in the last 90 degrees, crenulated inclusion trails and secondary Mn maxima centred on distinct crystallographic garnet domains are observed. Microstructural, geochemical and textural data indicate a…