New results on ternary InGaAs crystals grown using liquid encapsulated Czochralski technique with constant liquid composition are reported. X-ray high-resolution diffractometry (rocking curves and reciprocal space maps) as well as X-ray topography using the transmission Lang setup were used. Growth history of the bulk ingots was revealed.
This paper reports the use of a differential PDF approach performed on a laboratory X-ray diffractometer, for the analysis of nanosized PdO phase distributed on the reducible Fe₂O₃ support.
[Fe₃(hyetrz)₆(H₂O)₆](CF₃SO₃)₆ (where hyetrz = 4-(2'-hydroxyethyl)-1,2,4-triazole) is an interesting linear, trinuclear iron(II) compound with incomplete spin crossover. We reinvestigated crystal structure of this compound in the wide temperature range because the knowledge only about the crystal structure in the initial and final phases is not sufficient to establish correlations between the structural and magnetic properties of the spin crossover system. The complex [Zn₃(hyetrz)₆(H₂O)₆](CF₃SO₃)₆ was used for comparison because it does not exhibit spin crossover phenomenon and it is isostructural with a high spin phase of Fe(II).
Theoretically the X-ray emission is subjected to the Gaussian distribution and is symmetric. An X-ray diffraction peak should be symmetric, too. However all illite 1 nm (interplanar distance) peaks used for measurement of illite crystallinity (IC) are practically asymmetric. Our experimental results prove that any X-ray diffraction peak in low diffraction angle segment appears asymmetric if the diffractometer is running with a slit-fixed system. However, if the diffractometer is running with an auto-adjustable-slit system and the illumination length is fixed, the X-ray diffraction peak in low diffraction angle segment is symmetric. Those peaks derived from synchrotron radiation are symmetric in all angle ranges. The asymmetric degree (AsD) of a X-ray diffraction peak is subjected to the ratio of integrated intensities on lower and higher diffraction angle sides which are related to the X-ray illuminating length (area) on the sample. From the expression of illuminating length it is derived that with increasing diffraction angle the illuminating length decreases and therefore a X-ray diffraction peak is always asymmetric. The relationship between AsD and IC can be expressed as AsD = 0.239IC + 0.999, When illite/smectite mixed-layer phase presents the asymmetry of the illite 1 nm X-ray diffraction peak will be obviously higher than usual case and induces unusually larger IC value.
The Ni-Ti-Zr metallic glasses are due to their known shape memory properties promising alloys e.g. for micromechanical applications. In this paper structure and structure stability of one particular alloy Ni₆₀Ti₂₅Zr₁₅ at.% were examined by means of X-ray diffraction and transmission electron microscopy while magnetic properties were ascertained by vibrating-sample magnetometer with maximal applied field of 100 kA/m in the temperature range of 300-1073 K.
Nanocrystalline samples of Fe_{80}Mo_{20} and Fe_{50}Mo_{50} alloys were prepared by the mechanical milling method. The structure, lattice parameters, and crystallite size were determined by the X-ray diffraction. The magnetic properties of the milled products were determined by the M"ossbauer spectroscopy. It was observed that in the case of the Fe_{80}Mo_{20} alloy a solid solution of Mo in Fe was formed with the lattice parameters of Fe increasing from 0.28659 nm to 0.29240 nm and the crystallite size decreasing from 250 nm to 20 nm. In the case of the Fe_{50}Mo_{50} alloy there were no clear changes in values of the lattice parameters of Fe and Mo during the milling process, but the crystallite size decreased from 200 nm to 15 nm. Mössbauer spectra revealed different magnetic phases in the mechanosynthesized Fe-Mo samples. In the case of the Fe_{80}Mo_{20} alloy, the spectrum for the milled mixture indicated the formation of a solid solution. In contrast, for the Fe_{50}Mo_{50} the spectrum indicated the disappearance of the ferromagnetic phase.
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