Error Analysis and Correction for Quantitative Phase Analysis Based on Rietveld-Internal Standard Method: Whether the Minor Phases Can Be Ignored?

Zhao, Piqi; Lu, Lingchao; Liu, Xianping; Torre, Ángeles G. De la; Cheng, Xin

doi:10.3390/cryst8030110

Cited by 36 publications

(15 citation statements)

References 32 publications

(42 reference statements)

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“…It should be noted that no Cu 2 O phase formation was recorded during the annealing of samples in the specified temperature range. The phase composition was determined using the Rietveld method, which is based on estimating the areas of diffraction peaks by approximating them and determining convergence with reference values for each phase [47,48]. In case of the predominance of amorphous structures such as the PET template, the phase composition is determined based on the most intense peak, which in our case is CuO (111) [49].…”

Section: Synthesis and Thermal Annealing Of Cu/pet Compositesmentioning

confidence: 99%

Cu/CuO Composite Track-Etched Membranes for Catalytic Decomposition of Nitrophenols and Removal of As(III)

et al. 2020

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One of the promising applications of nanomaterials is to use them as catalysts and sorbents to remove toxic pollutants such as nitroaromatic compounds and heavy metal ions for environmental protection. This work reports the synthesis of Cu/CuO-deposited composite track-etched membranes through low-temperature annealing and their application in catalysis and sorption. The synthesized Cu/CuO/poly(ethylene terephthalate) (PET) composites presented efficient catalytic activity with high conversion yield in the reduction of nitro aryl compounds to their corresponding amino derivatives. It has been found that increasing the time of annealing raises the ratio of the copper(II) oxide (CuO) tenorite phase in the structure, which leads to a significant increase in the catalytic activity of the composites. The samples presented maximum catalytic activity after 5 h of annealing, where the ratio of CuO phase and the degree of crystallinity were 64.3% and 62.7%, respectively. The catalytic activity of pristine and annealed composites was tested in the reduction of 4-nitroaniline and was shown to remain practically unchanged for five consecutive test cycles. Composites annealed at 140 °C were also tested for their capacity to absorb arsenic(III) ions in cross-flow mode. It was observed that the sorption capacity of composite membranes increased by 48.7% compared to the pristine sample and reached its maximum after 10 h of annealing, then gradually decreased by 24% with further annealing.

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Section: Synthesis and Thermal Annealing Of Cu/pet Compositesmentioning

confidence: 99%

Cu/CuO Composite Track-Etched Membranes for Catalytic Decomposition of Nitrophenols and Removal of As(III)

et al. 2020

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“…The amorphous and impurity crystal phases can play a substantial role in increasing the CTE of the sintered honeycomb because these phases have larger CTEs than the cordierite polymorphs. The amounts of these phases analyzed by the Rietveld‐internal standard method are represented in Figure . The refinement profile obtained by the Rietveld‐internal standard method with the six phases, that is, spinel, silimanite, cristobalite (a high‐temperature polymorph of silica), ZnO, and two cordierite polymorphs, is represented in Figure S5, Supporting Information.…”

Section: Resultsmentioning

confidence: 99%

“…Quantitative determination of amorphous phase was carried out by the Rietveld‐internal standard refinement method, which is the most widely used technique. ZnO powder was used as an internal standard material.…”

Section: Methodsmentioning

confidence: 99%

Crystal Structure and Thermal Expansion Coefficient of Cordierite Honeycomb Ceramics

Son

Chae

Kim

et al. 2019

Physica Status Solidi (a)

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Cordierite honeycomb ceramics are sintered under a range of sintering atmosphere and temperature conditions. The linear thermal expansion coefficient (CTE) is measured along the extrusion direction. The samples sintered in an enclosed crucible have a much lower CTE than those sintered in open air. The CTE decreases with increasing sintering temperature up to 1450 C. The polymorphic phases, texture, amorphous phase, impurity crystals, and porosity are analyzed using scanning electron microscopy, HR-TEM, porosimeter, and Rietveld refinement method. The sintered samples consist of two polymorphic phases: indialite (hexagonal symmetry) and cordierite (orthorhombic symmetry). Both the volume % of the cordierite phase and the crystal texture increase with increasing sintering temperature. The orthorhombic distortion of cordierite from the hexagonal lattice (indialite) increases with increasing sintering temperature. The characteristic sixmembered ring of the (Si,Al)-O4 tetrahedra in the cordierite structure shows substantial changes in the bond length due to Al-Si ordering. Amorphous phase and impurity crystal phases such as silimanite and spinel remain at temperatures as high as 1450 C. The effect of the polymorphic phases, the degree of texture, amorphous phase, impurity crystal phases, and the orthorhombic distortion is discussed in relation to the CTE characteristics of honeycomb.

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“…In contrast, mineral phases produced distinct peaks when analyzed with XRD, with the intensity of the peak depending on the amount of the mineral phase present. However, the broad and low-intensity peaks of the amorphous phases can hide low-intensity peaks of mineral phases present in a small amount [59]. Therefore, the presence of the amorphous phase in the Plombières samples may have resulted in some minor and trace mineral phases being missed.…”

Section: Mineralogy Of Plombières Materialsmentioning

confidence: 99%

Geochemical and Mineralogical Characterisation of Historic Zn–Pb Mine Waste, Plombières, East Belgium

et al. 2020

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Mine wastes and tailings derived from historical processing may contain significant contents of valuable metals due to processing being less efficient in the past. The Plombières tailings pond in eastern Belgium was selected as a case study to determine mineralogical and geochemical characteristics of the different mine waste materials found at the site. Four types of material were classified: soil, metallurgical waste, brown tailings and yellow tailings. The distribution of the mine wastes was investigated with drill holes, pit-holes and geophysical methods. Samples of the materials were assessed with grain size analysis, and mineralogical and geochemical techniques. The mine wastes dominantly consist of SiO2, Al2O3 and Fe2O3. The cover material, comprising soil and metallurgical waste is highly heterogeneous in terms of mineralogy, geochemistry and grain size. The metallurgical waste has a high concentration of metals (Zn: 0.1 to 24 wt.% and Pb: 0.1 to 10.1 wt.%). In the tailings materials, Pb and Zn vary from 10 ppm to 8.5 wt.% and from 51 ppm to 4 wt.%, respectively. The mining wastes comprises mainly quartz, amorphous phases and phyllosilicates, with minor contents of Fe-oxide and Pb- and Zn-bearing minerals. Based on the mineralogical and geochemical properties, the different potential applications of the four waste material types were determined. Additionally, the theoretical economic potential of Pb and Zn in the mine wastes was estimated.

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Error Analysis and Correction for Quantitative Phase Analysis Based on Rietveld-Internal Standard Method: Whether the Minor Phases Can Be Ignored?

Cited by 36 publications

References 32 publications

Cu/CuO Composite Track-Etched Membranes for Catalytic Decomposition of Nitrophenols and Removal of As(III)

Cu/CuO Composite Track-Etched Membranes for Catalytic Decomposition of Nitrophenols and Removal of As(III)

Crystal Structure and Thermal Expansion Coefficient of Cordierite Honeycomb Ceramics

Geochemical and Mineralogical Characterisation of Historic Zn–Pb Mine Waste, Plombières, East Belgium

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