scholarly journals A trial for distinguish of Mn3+ and Mn4+ ions in LiMn2O4 by anomalous powder x-ray diffraction with focused beam flat sample method

2019 ◽  
Author(s):  
Masahiko Tanaka ◽  
Kunio Yubuta ◽  
Yoshio Katsuya ◽  
Osami Sakata
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
Flat Sample ◽  
Sample Method ◽  
Focused Beam

Quantitative phase analysis in the Ti–Al–C ternary system by X-ray diffraction

2005 ◽  
Vol 20 (3) ◽  
pp. 218-223 ◽  
Author(s):  
Chang-An Wang ◽  
Aiguo Zhou ◽  
Liang Qi ◽  
Yong Huang
Keyword(s):  
Ternary System ◽  
Phase Analysis ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
Internal Standards ◽  
X Ray ◽  
Quantitative Phase ◽  
Diffraction Peaks ◽  
Equation Group ◽  
Sample Method

Materials in the Ti–Al–C ternary system commonly contain three coexisting phases, Ti3AlC2, Ti2AlC, and TiC. Quantitative phase analysis in this ternary system was investigated using X-ray diffraction. First, nonoverlap diffraction peaks were selected: the (002) peak at 2θ=9.5° for Ti3AlC2 (I∕I0=26.5), the (002) peak at 2θ=13.0° for Ti2AlC (I∕I0=39), and the (111) peak at 2θ=35.9° for TiC (I∕I0=78), respectively. Then, based on the mixing-sample method without internal standards, a set of equations was derived for determining the amounts of Ti3AlC2, Ti2AlC, and TiC in a sample using the intensities of the selected diffraction peaks. Finally, the applicability and error sources for this method were investigated. The method is simple and straightforward, and is applicable to the entire Ti–Al–C ternary system, since the derivation of this equation group is self-checking.

scholarly journals Measurement of persistence in YAG:Ce3+scintillator with pulsed synchrotron X-rays

2011 ◽  
Vol 18 (4) ◽  
pp. 601-604 ◽  
Author(s):  
Tatsuhito Matsuo ◽  
Naoto Yagi
Keyword(s):  
High Resolution ◽  
Decay Time ◽  
Periodic Variation ◽  
Frame Rate ◽  
X Rays ◽  
X Ray Diffraction ◽  
Cmos Camera ◽  
X Ray ◽  
Space Resolution ◽  
Focused Beam

The decay time of YAG:Ce3+phosphor was studied using a CMOS camera with a frame rate of 1302000 s−1and pulsed X-rays from SPring-8. A high-resolution X-ray detector with YAG:Ce3+was used with the camera to view the focused beam from the helical undulator. Mismatch between the ring circulation time and the frame time gave rise to a periodic variation of beam intensity in successive frames. Analysis of data obtained with two bunch modes showed that the decay time of YAG:Ce3+was 60 ns. The variation of the beam positions in isolated bunches was small enough to be neglected in experiments using the focused beam. The results also show the possibility of an X-ray diffraction study at high time and space resolution.

scholarly journals X-ray diffraction reveals the amount of strain and homogeneity of extremely bent single nanowires

2020 ◽  
Vol 53 (5) ◽  
pp. 1310-1320
Author(s):  
Arman Davtyan ◽  
Dominik Kriegner ◽  
Václav Holý ◽  
Ali AlHassan ◽  
Ryan B. Lewis ◽  
...  
Keyword(s):  
Lattice Mismatch ◽  
Diffraction Theory ◽  
Strain Engineering ◽  
Strain Variation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Single Nanowires ◽  
Bent Crystals ◽  
Focused Beam ◽  
Shell Nanowires

Core–shell nanowires (NWs) with asymmetric shells allow for strain engineering of NW properties because of the bending resulting from the lattice mismatch between core and shell material. The bending of NWs can be readily observed by electron microscopy. Using X-ray diffraction analysis with a micro- and nano-focused beam, the bending radii found by the microscopic investigations are confirmed and the strain in the NW core is analyzed. For that purpose, a kinematical diffraction theory for highly bent crystals is developed. The homogeneity of the bending and strain is studied along the growth axis of the NWs, and it is found that the lower parts, i.e. close to the substrate/wire interface, are bent less than the parts further up. Extreme bending radii down to ∼3 µm resulting in strain variation of ∼2.5% in the NW core are found.

Polytypism in GaAs nanowires: determination of the interplanar spacing of wurtzite GaAs by X-ray diffraction

2015 ◽  
Vol 22 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Martin Köhl ◽  
Philipp Schroth ◽  
Andrey A. Minkevich ◽  
Jean-Wolfgang Hornung ◽  
Emmanouil Dimakis ◽  
...  
Keyword(s):  
Interplanar Spacing ◽  
Stacking Sequence ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zinc Blende ◽  
Gaas Nanowires ◽  
Mean Diameter ◽  
Order Of Magnitude ◽  
Focused Beam

In GaAs nanowires grown along the cubic [111]cdirection, zinc blende and wurtzite arrangements have been observed in their stacking sequence, since the energetic barriers for nucleation are typically of similar order of magnitude. It is known that the interplanar spacing of the (111)cGa (or As) planes in the zinc blende polytype varies slightly from the wurtzite polytype. However, different values have been reported in the literature. Here, the ratio of the interplanar spacing of these polytypes is extracted based on X-ray diffraction measurements for thin GaAs nanowires with a mean diameter of 18–25 nm. The measurements are performed with a nano-focused beam which facilitates the separation of the scattering of nanowires and of parasitic growth. The interplanar spacing of the (111)cGa (or As) planes in the wurtzite arrangement in GaAs nanowires is observed to be 0.66% ± 0.02% larger than in the zinc blende arrangement.

Micro X-ray diffraction analysis of thin films using grazing-exit conditions

1998 ◽  
Vol 5 (3) ◽  
pp. 902-904 ◽  
Author(s):  
Takashi Noma ◽  
Atsuo Iida
Keyword(s):  
Sample Surface ◽  
Exit Angle ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Sensitivity ◽  
Refraction Effect ◽  
Glancing Angle ◽  
Diffraction Patterns ◽  
Focused Beam

An X-ray diffraction technique using a hard X-ray microbeam for thin-film analysis has been developed. To optimize the spatial resolution and the surface sensitivity, the X-ray microbeam strikes the sample surface at a large glancing angle while the diffracted X-ray signal is detected with a small (grazing) exit angle. Kirkpatrick–Baez optics developed at the Photon Factory were used, in combination with a multilayer monochromator, for focusing X-rays. The focused beam size was about 10 × 10 µm. X-ray diffraction patterns of Pd, Pt and their layered structure were measured. Using a small exit angle, the signal-to-background ratio was improved due to a shallow escape depth. Under the grazing-exit condition, the refraction effect of diffracted X-rays was observed, indicating the possibility of surface sensitivity.

scholarly journals The Spherical Sample Method in Neutron Diffraction Texture Determination

Texture ◽  
1972 ◽  
Vol 1 (2) ◽  
pp. 125-127 ◽  
Author(s):  
J. Tobisch ◽  
H. J. Bunge
Keyword(s):  
Neutron Diffraction ◽  
Absorption Coefficient ◽  
Texture Analysis ◽  
Fundamental Difference ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spherical Sample ◽  
Broad Variety ◽  
Sample Method

Neutron diffraction proves advantageous as compared to X-ray diffraction in texture analysis because of the lower absorption coefficient for a broad variety of materials especially metals. The spherical sample method is recommended because it yields the most reliable results and it does not require great preparational efforts. The fundamental difference between the spherical sample method in X-ray and in neutron diffraction is discussed.

Design and performance of a focused beam line for surface x‐ray diffraction

1992 ◽  
Vol 63 (1) ◽  
pp. 1083-1086 ◽  
Author(s):  
C. Norris ◽  
M. S. Finney ◽  
G. F. Clark ◽  
G. Baker ◽  
P. R. Moore ◽  
...  
Keyword(s):  
Beam Line ◽  
X Ray Diffraction ◽  
X Ray ◽  
And Performance ◽  
Focused Beam

scholarly journals Using refractive optics to broaden the focus of an X-ray mirror

2017 ◽  
Vol 24 (4) ◽  
pp. 744-749 ◽  
Author(s):  
David Laundy ◽  
Kawal Sawhney ◽  
Vishal Dhamgaye
Keyword(s):  
Focal Spot ◽  
X Rays ◽  
Beam Size ◽  
X Ray Diffraction ◽  
Size Change ◽  
Optical Elements ◽  
X Ray ◽  
High Data ◽  
Radiation Sources ◽  
Focused Beam

X-ray mirrors are widely used at synchrotron radiation sources for focusing X-rays into focal spots of size less than 1 µm. The ability of the beamline optics to change the size of this spot over a range up to tens of micrometres can be an advantage for many experiments such as X-ray microprobe and X-ray diffraction from micrometre-scale crystals. It is a requirement that the beam size change should be reproducible and it is often essential that the change should be rapid, for example taking less than 1 s, in order to allow high data collection rates at modern X-ray sources. In order to provide a controlled broadening of the focused spot of an X-ray mirror, a series of refractive optical elements have been fabricated and installed immediately before the mirror. By translation, a new refractive element is moved into the X-ray beam allowing a variation in the size of the focal spot in the focusing direction. Measurements using a set of prefabricated refractive structures with a test mirror showed that the focused beam size could be varied from less than 1 µm to over 10 µm for X-rays in the energy range 10–20 keV. As the optics is in-line with the X-ray beam, there is no effect on the centroid position of the focus. Accurate positioning of the refractive optics ensures reproducibility in the focused beam profile and no additional re-alignment of the optics is required.

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