High Temperature - FTIR Characterization of Gadolinia Doped Ceria

2010 ◽  
Vol 72 ◽  
pp. 249-254
Author(s):  
Aliye Arabaci ◽  
Nuri Solak
Keyword(s):  
High Temperature ◽  
Thermal Analyses ◽  
Water Soluble ◽  
Ex Situ ◽  
Doped Ceria ◽  
X Ray Diffraction ◽  
Ftir Characterization ◽  
Ft Ir ◽  
Xrd Techniques

Doped ceria-based (DC) materials have recently been considered as the most promising solid electrolytes for intermediate temperature solid oxide fuel cell (IT-SOFC) applications. Doped ceria is usually prepared via thermal decomposition of its water soluble salts, especially, acetates and nitrates. The properties of the obtained final product directly influenced by the starting material and the decomposition products. Therefore, it is crucial to understand the decomposition steps and intermediate products. Number of experimental work have been reported using various <em>in-situ</em> and <em>ex-situ</em> techniques such as thermogravimetry with mass spectrometry (TG/DTA-MS), X-ray diffraction with differential scanning calorimeter (XRD-DSC). However, the available literature data is limited and not reasonably in agreement with each other. High Temperature FT-IR spectroscopy, TG/DTA-MS, XRD, techniques were used and results are compared with literature. A good agreement between the thermal analyses and HT-FTIR results were obtained. Possible decomposition mechanism is discussed.

scholarly journals XRD-Thermal Combined Analyses: An Approach to Evaluate the Potential of Phytoremediation, Phytomining, and Biochar Production

2019 ◽  
Vol 16 (11) ◽  
pp. 1976 ◽  
Author(s):  
Dario Fancello ◽  
Jessica Scalco ◽  
Daniela Medas ◽  
Elisa Rodeghero ◽  
Annalisa Martucci ◽  
...  
Keyword(s):  
Thermal Analyses ◽  
Xrd Analysis ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Juncus Acutus ◽  
Polluted Sites ◽  
Synchrotron Light ◽  
In Situ Heating

A method for evaluating the potential of reuse of biomasses for economic purposes is here presented starting from a case study. Juncus acutus plants and rhizospheres were harvested from abandoned Zn–Pb mine areas of southwest Sardinia (Italy). Thermogravimetry and Differential Thermal analyses were performed to evaluate the temperatures at which significant reactions occur. X-ray Diffraction (XRD) analysis was carried out on raw samples and on samples heated ex-situ (by a conventional diffractometer) or in-situ (by synchrotron-based diffraction). Raw samples mainly consist of quartz, phyllosilicates, and feldspars with minor amounts of sulfides, sulfates, and Fe, Pb, and Zn carbonates, concentrated in the rhizosphere. After heating, Zn and Fe oxides and willemite are observed in internal roots and stems, revealing the presence of these metals in the plant tissues. In-situ heating was less effective than ex-situ in revealing minor phases in organic samples, probably because the scarcity of oxygen within the sample holder did not allow the degradation of organic compounds and the oxidation of sulfides, resulting in a low quality XRD signal even if obtained with the high resolution ensured by a synchrotron light source. This method can be applied to plants from polluted sites for metal exploitation, and/or to biomasses from unpolluted sites for biochar production, since both applications take advantage of the knowledge of the minerals formed after heating.

Observation of a Collapsing Layer Structure in Mg/Al Layered Double Hydroxides with Interlayer Hydrogen Phosphate by High Temperature In Situ X-Ray Diffraction with Synchrotoron Radiation

2011 ◽  
Vol 700 ◽  
pp. 67-70
Author(s):  
Akihiro Shimamura ◽  
Linus Perander ◽  
Eiji Kanezaki ◽  
Mark Ian Jones ◽  
James B. Metson
Keyword(s):  
High Temperature ◽  
Thermal Behavior ◽  
Layered Double Hydroxides ◽  
Layer Structure ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Hydrogen Phosphate ◽  
X Ray ◽  
Double Hydroxides

The collapsing layer structure of hydrogen phosphate intercalated Mg/Al-layered double hydroxides (LDH-HPO4) was investigated by high temperature in-situ X-ray diffraction with synchrotron radiation (in-situ XRD). The thermal behavior of the layer structure of LDH-HPO4 showed the same behavior in both in-situ and ex-situ XRD up until 109 °C as previously reported. The basal spacing of LDH-HPO4 continuously decreases above this temperature and finally the layer structure of LDH-HPO4 collapses. Another diffraction peak, d110, which gives a lattice constant a0, decreases at 62 °C, keeps constant to 120°C, increases up to 176°C and again keeps constant until the layer collapse. In this study, the different thermal behavior is observed between two reflections by in-situ XRD measurement, which explains the mechanism of the collapse of the layer structure in LDH-HPO4.

scholarly journals High-temperature Fe oxidation coupled with redistribution of framework cations in lobanovite, K2Na(Fe2+ 4Mg2Na)Ti2(Si4O12)2O2(OH)4 – the first titanosilicate case

2019 ◽  
Vol 75 (4) ◽  
pp. 578-590 ◽  
Author(s):  
Elena S. Zhitova ◽  
Andrey A. Zolotarev ◽  
Frank C. Hawthorne ◽  
Sergey V. Krivovichev ◽  
Viktor N. Yakovenchuk ◽  
...  
Keyword(s):  
High Temperature ◽  
Elevated Temperatures ◽  
Iron Oxidation ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Bond Strengths ◽  
Increasing Temperature

The high-temperature (HT) behaviour of lobanovite, K2Na(Fe2+ 4Mg2Na)Ti2(Si4O12)2O2(OH)4, was studied using in situ powder X-ray diffraction in the temperature range 25–1000°C and ex situ single-crystal X-ray diffraction of 17 crystals quenched from different temperatures. HT iron oxidation associated with dehydroxylation starts at 450°C, similar to other ferrous-hydroxy-rich heterophyllosilicates such as astrophyllite and bafertisite. A prominent feature of lobanovite HT crystal chemistry is the redistribution of Fe and Mg+Mn cations over the M(2), M(3), M(4) sites of the octahedral (O) layer that accompanies iron oxidation and dehydroxylation. This HT redistribution of cations has not been observed in titanosilicates until now, and seems to be triggered by the need to maintain bond strengths at the apical oxygen atom of the TiO5 pyramid in the heteropolyhedral (H) layer during oxidation–dehydroxylation. Comparison of the HT behaviour of lobanovite with five-coordinated Ti and astrophyllite with six-coordinated Ti shows that the geometry of the Ti polyhedron plays a key role in the HT behaviour of heterophyllosilicates. The thermal expansion, geometrical changes and redistribution of site occupancies which occur in lobanovite under increasing temperature are reported. A brief discussion is given of minerals in which the cation ordering (usually for Fe and Mg) occurs together with iron oxidation–dehydroxylation at elevated temperatures: micas, amphiboles and tourmalines. Now this list is expanded by the inclusion of titanosilicate minerals.

Devitrification products of rapidly solidified Ni-Nb amorphous alloys.

1990 ◽  
Vol 48 (4) ◽  
pp. 950-951
Author(s):  
G. A. Bertero ◽  
W.H. Hofmeister ◽  
N.D. Evans ◽  
J.E. Wittig ◽  
R.J. Bayuzick
Keyword(s):  
Electron Microscopy ◽  
Amorphous Structure ◽  
Sulphuric Acid Solution ◽  
X Ray Diffraction ◽  
High Fracture ◽  
Transmission Electron ◽  
Xrd Techniques ◽  
Rapidly Solidified ◽  
Electromagnetically Levitated

Rapid solidification of Ni-Nb alloys promotes the formation of amorphous structure. Preliminary results indicate promising elastic properties and high fracture strength for the metallic glass. Knowledge of the thermal stability of the amorphus alloy and the changes in properties with temperature is therefore of prime importance. In this work rapidly solidified Ni-Nb alloys were analyzed with transmission electron microscopy (TEM) during in-situ heating experiments and after isothermal annealing of bulk samples. Differential thermal analysis (DTA), scanning electron microscopy (SEM) and x-ray diffraction (XRD) techniques were also used to characterize both the solidification and devitrification sequences.Samples of Ni-44 at.% Nb were electromagnetically levitated, melted, and rapidly solidified by splatquenching between two copper chill plates. The resulting samples were 100 to 200 μm thick discs of 2 to 3 cm diameter. TEM specimens were either ion-milled or alternatively electropolished in a methanol-10% sulphuric acid solution at 20 V and −40°C.

In Situ X-Ray Diffraction Investigations during Diffusion Anneals of Ni-Cu Thin Film Diffusion Couples

2010 ◽  
Vol 89-91 ◽  
pp. 503-508 ◽  
Author(s):  
J. Sheng ◽  
U. Welzel ◽  
Eric J. Mittemeijer
Keyword(s):  
Thermal Stresses ◽  
Stress Generation ◽  
Ex Situ ◽  
Diffusion Annealing ◽  
X Ray Diffraction ◽  
Individual Layer ◽  
X Ray ◽  
Bilayer System ◽  
Stress Changes

The stress evolution during diffusion annealing of Ni-Cu bilayers (individual layer thicknesses of 50 nm) was investigated employing ex-situ and in-situ X-ray diffraction measurements. Annealing at relatively low homologous temperatures (about 0.3 - 0.4 Tm) for durations up to about 100 hours results in considerable diffusional intermixing, as demonstrated by Auger-electron spectroscopy investigations (in combination with sputter-depth profiling). In addition to thermal stresses due to differences of the coefficients of thermal expansion of layers and substrate, tensile stress con-tributions in the sublayers arise during the diffusion anneals. The obtained stress data have been discussed in terms of possible mechanisms of stress generation. The influence of diffusion on stress development in the sublayers of the diffusion couple during heating and isothermal annealing was investigated by comparing stress changes in the bilayer system with corresponding results obtained under identical conditions for single layers of the components in the bilayer system. The specific residual stresses that emerge due to diffusion between the (sub)layers in the bilayer could thereby be identified.

One Step Synthesis and Characterization of Zirconia-Graphene Composites

2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  
Keyword(s):  
Synthesis And Characterization ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Composite ◽  
Transmission Electron ◽  
One Step ◽  
Ft Ir ◽  
Xrd Techniques

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.

scholarly journals In-Situ X-ray Diffraction Measurement for Pure Niobium Metal in High Temperature Hydrogen Atmosphere

2006 ◽  
Vol 70 (6) ◽  
pp. 467-472 ◽  
Author(s):  
Tomonori Nambu ◽  
Nobue Shimizu ◽  
Hisakazu Ezaki ◽  
Hiroshi Yukawa ◽  
Masahiko Morinaga ◽  
...  
Keyword(s):  
High Temperature ◽  
Hydrogen Atmosphere ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pure Niobium

The application of the in situ high-temperature X-ray diffraction quantitative analysis

2008 ◽  
Vol 452 (2) ◽  
pp. 446-450 ◽  
Author(s):  
Qiuguo Xiao ◽  
Ling Huang ◽  
Hui Ma ◽  
Xinhua Zhao
Keyword(s):  
High Temperature ◽  
Quantitative Analysis ◽  
X Ray Diffraction ◽  
X Ray
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