On influence of collimating slit imperfections on the quality of experimental data in high-resolution x-ray diffraction

2008 ◽  
Vol 372 (13) ◽  
pp. 2155-2158
Author(s):  
Aliaksandr V. Darahanau ◽  
Andrei Y. Nikulin ◽  
Ruben A. Dilanian
2014 ◽  
Vol 59 (3) ◽  
pp. 315-322 ◽  
Author(s):  
A. E. Blagov ◽  
A. L. Vasiliev ◽  
A. S. Golubeva ◽  
I. A. Ivanov ◽  
O. A. Kondratev ◽  
...  

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 61 ◽  
Author(s):  
Sondes Bauer ◽  
Adriana Rodrigues ◽  
Lukáš Horák ◽  
Xiaowei Jin ◽  
Reinhard Schneider ◽  
...  

Structural quality of LuFeO 3 epitaxial layers grown by pulsed-laser deposition on sapphire substrates with and without platinum Pt interlayers has been investigated by in situ high-resolution X-ray diffraction (reciprocal-space mapping). The parameters of the structure such as size and misorientation of mosaic blocks have been determined as functions of the thickness of LuFeO 3 during growth and for different thicknesses of platinum interlayers up to 40 nm. By means of fitting of the time-resolved X-ray reflectivity curves and by in situ X-ray diffraction measurement, we demonstrate that the LuFeO 3 growth rate as well as the out-of-plane lattice parameter are almost independent from Pt interlayer thickness, while the in-plane LuFeO 3 lattice parameter decreases. We reveal that, despite the different morphologies of the Pt interlayers with different thickness, LuFeO 3 was growing as a continuous mosaic layer and the misorientation of the mosaic blocks decreases with increasing Pt thickness. The X-ray diffraction results combined with ex situ scanning electron microscopy and high-resolution transmission electron microscopy demonstrate that the Pt interlayer significantly improves the structure of LuFeO 3 by reducing the misfit of the LuFeO 3 lattice with respect to the material underneath.


2014 ◽  
Vol 887-888 ◽  
pp. 446-449
Author(s):  
Dong Guo Zhang ◽  
Zhong Hui Li ◽  
Da Qing Peng ◽  
Xun Dong

The epitaxial growth of Gallium Nitride (GaN) on 2 inch Si (1 1 1) substrates was investigated, and it was found that by inserting a surface nitridation layer prior to Aluminum Nitride (AlN) nucleation upon substrate, the discoid defects and cracks on the surface were suppressed. Furthermore, compared with the GaN epitaxial layer grown without nitridation, the one with a 30 sec. nitridation layer showed a twice brighter integrated photoluminescence (PL) spectra intensity and a (0 0 2) High-resolution X-ray diffraction (HRXRD) curve width of 13.6 arcminute. The crystalline quality of GaN epitaxial layer became worse when the nitridation time exceeded a critical value, and even more cracks appeared on the surface although no discoid defect appeared anymore.


1997 ◽  
Vol 484 ◽  
Author(s):  
E. Abramof ◽  
S. O. Ferreira ◽  
P. H. O Rappl ◽  
A. Y. Ueta ◽  
C. Boschetti ◽  
...  

AbstractCaF2 layers were grown by molecular beam epitaxy on differently prepared Si(111) substrates. X-ray reflectivity spectra were measured and fitted. From the fitting process, the thickness of the CaF2 layer was precisely (within 1 Å) determined and the CaF2/Si interface roughness was also obtained. This roughness was used as an evaluation parameter for the quality of the layers. The CaF2/Si sample from which the intentional oxide was desorpted at 800°C inside the growth chamber exhibited the most clear x-ray reflectivity spectrum with very well resolved interference fringes. The epitaxial relations of the CaF2/Si samples grown at temperatures between 250 and 700°C were determined from x-ray diffraction analysis.


1989 ◽  
Vol 145 ◽  
Author(s):  
J. M. Vandenberg

AbstractHigh-resolution x-ray diffraction (HRXRD) measurements of strained-layer superlattices (SLS's) have been carried out using a four-crystal monochromator. A wide asymmetric range of sharp higher-order x-ray satellite peaks is observed indicating well-defined periodic structures. Using a kinematical diffraction step model very good agreement between measured and simulated x-ray satellite patterns could be achieved. These results show that this x-ray method is a powerful tool to evaluate the crystal quality of SLS's.


2005 ◽  
Vol 38 (5) ◽  
pp. 740-748
Author(s):  
Marco Servidori ◽  
Giampiero Ottaviani

High-resolution multi-crystal X-ray diffraction was employed to characterize silicon-on-nothing samples consisting of a one-dimensional periodic array of buried empty channels.p- andn-type silicon starting wafers were used for sample preparation. For thep-type samples, this periodic array gives rise to well defined Fraunhofer diffraction when the channels are normal to the scattering plane. This indicates good lattice quality of the layer containing the channels. Moreover, the lattices of the surface layer and the layer with the channels were almost indistinguishable from that of perfect silicon. Conversely, then-type samples showed such lattice tilts and out-of-plane mosaic spreads in the surface and buried layers that Fraunhofer diffraction does not occur from the periodic array of the channels. The elucidation of this different behaviour is in progress and will most likely be fruitful after X-ray images of the same samples are taken.


2011 ◽  
Vol 44 (2) ◽  
pp. 313-318 ◽  
Author(s):  
Krishnamurthy Senthil Kumar ◽  
Sridharan Moorthy Babu ◽  
G. Bhagavannarayana

Good quality and optically transparent single crystals of pure and doped glycine phosphite (GPI) were grown by both solvent-evaporation and temperature-cooling techniques. Dopants were chosen in different categories, namely transition metals (Cr, Mn, Co, Ni, Zn, Mg, Cd), rare-earth metals (Ce, Nd, La), dyes (rhodamine B, malachite green, fluorescein) and an amino acid (L-proline). The concentration of dopants was chosen depending on the category of dopants and the quality of crystallization during the growth process. The crystalline perfection of the as-grown pure and doped GPI crystals was investigated by high-resolution X-ray diffraction at room temperature. A multicrystal X-ray diffractometer employing a well collimated and highly monochromated Mo Kα1beam and set in the (+, −, −, +) configuration was employed. Most of the crystal specimens show excellent crystalline perfection. However, grain boundaries, low-angle tilt boundaries, and vacancy and interstitial point defects were observed in some crystal specimens.


2007 ◽  
Vol 22 (3) ◽  
pp. 219-222
Author(s):  
W. J. Wang ◽  
K. Sugita ◽  
Y. Nagai ◽  
Y. Houchin ◽  
A. Hashimoto ◽  
...  

The growth temperature dependence of the InN film’s crystalline quality is reported. InN films are grown on sapphire substrates from 570 to 650 °C with low-temperature GaN buffers by metalorganic vapor phase epitaxy (MOVPE). The X-ray rocking curves and reciprocal space mappings of the symmetric reflection (0 0 0 2) and asymmetric reflection (1 0 1 2) are measured with high resolution X-ray diffraction. The results indicate that the crystallinity is sensitive to the growth temperature for MOVPE InN. At growth temperature 580 °C, highly crystalline InN film has been obtained, for which the full-width-at-half-maxima of (0 0 0 2) and (1 0 1 2) rocking curves are 24 and 28 arcmin, respectively. The crystalline quality deteriorates drastically when the growth temperature exceeds 600 °C. Combined with the carrier concentration and mobility, the approach to improve the quality of InN film by MOVPE is discussed.


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