XRD

The main component of this program is a simultaneous representation of the unit cell and the calculated powder pattern. It allows the manipulation of the crystal structure by moving selected atoms of the asymmetric unit. The resulting powder pattern can be directly compared to experimental data in order to obtain reliable starting values for further computations in refinement programs.

Boron doped and undoped Poly(vinyl) alcohol/Zirconium-yttrium acetate (PVA/Zr-Y) nanofibers were prepared by electrospinning using PVA as a precursor. The effect of boron doping was investigated in terms of solution properties, morphological changes and thermal properties. The effect of boron doping on calcined yttria stabilized zirconia (YSZ) fibers were evaluated by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy analysis. XRD
analysis revealed varying amounts of monoclinic and tetragonal zirconia present in the undoped fibers calcined at 800oC. The average crystallite sizes of the undoped YSZ were increased from 9.28 to 22.79 nm with calcining temperature increasing from 250 to 800 °C. The crystallite size was enhanced with boron doping. The systematic evolution of morphological features in the spun and the processed fibers were employed by scanning electron microscopy.

Fluorite ornaments have been recorded in different sites of Europe since Upper Paleolithic. Due to its visual appearance and physical properties, some translucent or transparent mineralogies like fluorite were searched for or casually acquired by late prehistory’s human communities. After intensive research on archaeological contexts from the Iberian Peninsula with personal ornaments from 4th to 2nd millennia BCE, we have recently identified and characterized for the first time an important number of fluorite ornaments, confronting a previous background where little attention was paid. Our work has been carried out in different archaeological collections and museums from the whole Iberian Peninsula by non-destructive techniques (Raman spectroscopy, portable X-ray fluorescence (p-XRF) and X-ray Diffraction (XRD), that revealed the nature of fluorite ornaments and points to its consideration as scarce and highly symbolic items during late prehistory. A total of 36 fluorite beads from ...

In the quest to develop a green cement composite with the lowest possible carbon footprint and the highest possible use of industrial by-products, an experimental investigation was undertaken, replacing 100% of ordinary portland cement. This paper presents the results of an experimental program to develop a zero-cement composite, incorporating 2.5, 5, and 7.5% nanosilica, 72.5, 70, and 67.5% fly ash, 25% ground granulated blast furnace slag (GGBFS), and hydrated lime used as a cement additive at 10 and 15% of the total supplementary cementitious material. Compressive strength tests were undertaken to study the mechanical properties of mortar samples of various mix designs. In addition, scanning electron microscopy, thermogravimetry, and X-ray diffraction were undertaken in conjunction with quantitative phase analysis to investigate the various physicochemical changes taking place within the cement matrix and to formulate strategies for its further development. The results demonstrate that the addition of nanosilica and hydrated lime to low calcium/high-volume fly ash and GGBFS blend can help in achieving an environmentally friendly zero-cement composite without the need of any heat treatment. The optimum content of nanosilica was found to be 5%. With the further increase in nanosilica content, although the pozzolanic reaction and the resulting C–S–H/C–A–S–H gel formation increases, it also increases the microcracking within the cement matrix, resulting in the reduction in compressive strength at both 7 and 28 days of curing. The siliceous hydrogarnet formed as a result of the pozzolanic reaction of amorphous silica (FA, GGBFS, NS), with the calcium aluminate present in GGBFS, shows very poor crystallinity with no visible peak reflection in X-ray diffraction data. The formation of siliceous hydrogarnet increases with the increase in amorphous nanosilica, but decreases with the increase in hydrated lime content.

Single-crystals of MnFe2O4 nanorods with an average diameter of 20 nm and length of 250 nm were synthesized by a hydrothermal process at 180 °C after 12 h. High-resolution transmission electron microscopy (HRTEM) and electron diffraction (ED) analysis revealed that the nanorods grow along the [110] axis, which is one of the easy magnetization axes of the material MnFe2O4. It was found that the nanorods exhibited a saturation magnetization (Ms) of 68.02 emu/g, which is much higher than that of quasi-spherical particles of MnFe2O4, prepared by other approaches such as solid-state reaction methods (Ms = 36.7 emu/g), and coprecipitation processes followed by annealing in vacuo at 400 °C (Ms = 24.4 emu/g). The oriented growth along the easy magnetization axis of MnFe2O4 was suggested to be responsible for the improvement of magnetic properties of MnFe2O4 nanorods. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

MWCNT (Multiwalled carbon nanotubes) doped CuO (Copper oxide) nano flakeslike structure was prepared by complex precipitation method. XRD(X-ray dif raction) pattern showed the presence of phases assigned to CuO and dif erent phases of MWCNT, SEM (Scanning electron microscopy) images revealed the morphology of the prepared sample. FTIR(Fourier-transform infrared) spectroscopy techniques were depicted the minority groups present in the MWCNT doped CuO nanostructure. Optical transitions were obtained by PL(Photo Luminescence). Quantum confinement effects along with decrease bandgap for direct and indirect optical transitions of MWCNT doped CuO nanostructures in sansevieria trifasciata dye solution were reflected through UV-Visible spectroscopy

GaN epifilms are grown on the patterned sapphire substrates (PSS) (0001) and the conventional sapphire substrates (CSS) (0001) by metal-organic chemical vapor deposition (MOCVD) using a novel two-step growth. High resolution X-ray diffraction (HR-XRD) is used to investigate the threading dislocation (TD) density of the GaN epifilms. The TD density is calculated from the ω-scans full width at half maximum (FWHM) results of HR-XRD. The edge dislocation destiny of GaN grown on the PSS is 2.7×108 cm−2, which is less than on the CSS. This is confirmed by the results of atomic force microscopy (AFM) measurement. The lower TD destiny indicates that the crystalline quality of the GaN epifilms grown on the PSS is improved compared to GaN epifilms grown on the CSS. The residual strains of GaN grown on the PSS and CSS are compared by Raman Scattering spectra. It is clearly seen that the residual strain in the GaN grown on PSS is lower than on the CSS.

X-band and high-frequency EPR spectroscopy were used for studying the manganese environment in layered Li[Mg xNi 0.5-xMn 0.5]O 2, 00.5Mn 0.5O 2 and monoclinic Li[Li 1/3Mn 2/3]O 2 oxides (containing Mn 4+ ions only) were used as EPR standards. The EPR study was extended to the Ni-substituted analogues, where both Ni 2+ and Mn 4+ are paramagnetic. For LiMg 0.5-xNi xMn 0.5O 2 and Li[Li (1-2x)/3Ni xMn (2-x)/3]O 2, an EPR response from Mn 4+ ions only was detected, while the Ni 2+ ions remained EPR silent in the frequency range of 9.23-285 GHz. For the diamagnetically diluted oxides, LiMg 0.25Ni 0.25Mn 0.5O 2 and Li[Li 0.10Ni 0.35Mn 0.55]O 2, two types of Mn 4+ ions located in a mixed (Mn-Ni-Li)-environment and in a Ni-Mn environment, respectively, were registered by high-field experiments. In the X-band, comparative analysis of the EPR line width of Mn 4+ ions permits to extract the composition of the first coordination sphere of Mn in layered LiMg 0.5-xNi xMn 0.5O 2 (0(1-2x)/3Ni xMn (2-x)/3]O 2 ( x>0.2). It was shown that a fraction of Mn 4+ are in an environment resembling the ordered " alpha, beta"-type arrangement in Li 1-delta1Ni delta1[Li (1-2x)/3+delta1Ni 2x/3-delta1) alpha(Mn (2-x)/3Ni x/3) beta]O 2 (where x={2}/{7} and delta1=0.06 were calculated), while the rest of Mn 4+ are in the Ni,Mn-environment corresponding to the Li 1-delta2Ni delta2[Ni 1-yMn y]O 2 ( y<{1}/{2}) composition with a statistical Ni,Mn distribution. For Li[Li (1-2x)/3Ni xMn (2-x)/3]O 2 with x1/3Mn 2/3]O 2.