New high- and low-temperature apparatus for synchrotron polycrystalline X-ray diffraction

1998 ◽  
Vol 5 (3) ◽  
pp. 929-931 ◽  
Author(s):  
C. C. Tang ◽  
G. Bushnell-Wye ◽  
R. J. Cernik

A high-temperature furnace with an induction heater coil and a cryogenic system based on closed-cycle refrigeration have been assembled to enhance the non-ambient powder diffraction facilities at the Synchrotron Radiation Source, Daresbury Laboratory. The commissioning of the high- and low-temperature devices on the high-resolution powder diffractometer of Station 2.3 is described. The combined temperature range provided by the furnace/cryostat is 10–1500 K. Results from Fe and NH4Br powder samples are presented to demonstrate the operation of the apparatus. The developments presented in this paper are applicable to a wide range of other experiments and diffraction geometries.

2016 ◽  
Vol 703 ◽  
pp. 87-93 ◽  
Author(s):  
Cui Can Wang ◽  
Chang Lian Chen ◽  
Ma Yo Luo ◽  
Xiao Yu Huang ◽  
Zhi Liang Huang

In order to research the toughening effects of carbon nanotubes on 3Y-ZrO2 via different moulding methods. 3Y-ZrO2 and 3Y-ZrO2 with two kind of carbon nanotubes were prepared by compression moluding forming and gel-casting. And all of the green bodies were sintering at 1600°C in high temperature furnace. The X-ray diffraction and density of sintered bodies, microstructural of fracture surface and fracture toughness were characterized and analyzed. Results shown that gel-casting is better than compression about toughening 3Y-ZrO2 by carbon nanotubes. For gel-casting, the density is nearly the same and fracture toughness has been improved which is form 5.17MPa·m1/2 to 5.63 MPa·m1/2. For compression moulding forming, the density was reduced by the aggregation of carbon nanotubes. The fracture toughness can’t improve by carbon nanotubes.


1999 ◽  
Vol 32 (4) ◽  
pp. 833-836 ◽  
Author(s):  
Michael Estermann ◽  
Hans Reifler ◽  
Walter Steurer ◽  
Frank Filser ◽  
Peter Kocher ◽  
...  

A complex high-temperature furnace has been produced from presintered α-Al2O3precompacts. The furnace is designed for the Mar345 imaging-plate detector system. Up to now, the design complexity of ceramic parts has been limited by the difficulty of machining hard ceramic materials or by the moulds used in hot-pressing and casting. However, the machining of soft presintered ceramic materials enables the realisation of much more demanding designs, provided that the final sintering shrinkage of the ceramic is homogeneous and predictable. The design of the furnace and its realisation and application in an X-ray diffraction study with synchrotron radiation are presented.


1974 ◽  
Vol 39 (3) ◽  
pp. 477-483 ◽  
Author(s):  
Wayne C. Isphording

AbstractThe identification of the original paste and temper minerals present in ceramicware fragments can often be useful in determining if the fragments are indigenous to the area or whether they represent tradeware. To date, it has generally been believed that no certain means existed to identify the mineral constitutents once they were destroyed in the original kiln-firing operation. A new technique is described that permits the investigator to often identify both temper and the fine-grained paste materials as well. This method involves: (1) crushing the fragment to a fine powder; (2) heating the powder in a high temperature furnace to sufficient temperatures to cause the constituent ions present to recombine to form new, high temperature minerals; and (3) X-ray diffraction analysis to identify the new minerals. In many cases, identification of the resulting high temperature minerals will clearly indicate the composition of the original clay paste and temper. Examples are shown for the clay minerals kaolinite, montmorillonite and palygorskite. Diffractograms are also presented for comparison of ceramic fragments from Mexico and Alabama that contain the above minerals as original constituents.


1994 ◽  
Vol 337 ◽  
Author(s):  
Mansour Moinpour ◽  
Farhad Moghadam ◽  
Johnny Cham ◽  
Wen-Juei Lu

ABSTRACTCVD WSix films have been widely employed for ultra thin gate and bit-line applications. Recently, for sub 0.5 μm technologies based on CVD WSix polycide gates and interconnects, efforts have been made to replace the silane-based deposition chemistry with that based on dichlorosilane (DCS) reduction of tungsten hexafluoride (WF6). Fluorine-contaminated gate oxides and poor film adhesion and cracking (especially after high temperature annealing/oxidation) are main characteristics of silane-based WSix which could be detrimental for fine geometries of sub 0.5 |im technologies. In this paper, the composition and structure of DCS-based CVD WSix films were studied. WSix films were deposited on 200 mm, implanted polysilicon substrates; silicide film thickness ranging from 60 to 200nm. A high temperature furnace anneal and oxidation cycle was used to examine post-oxidation film properties. SIMS, RBS and X-ray diffraction (XRD) were used to determine film composition profile, structure and texture on both as-deposited and annealed/oxidized films. Si/W uniformity through the depth of the film, for both W-rich and Si-rich interfaces, and its impact on film adhesion and cracking were studied. Also, WSix step coverage for sub 0.5 μm polycide topographies were examined.


1961 ◽  
Vol 5 ◽  
pp. 276-284
Author(s):  
E. L. Moore ◽  
J. S. Metcalf

AbstractHigh-temperature X-ray diffraction techniques were employed to study the condensation reactions which occur when sodium orthophosphates are heated to 380°C. Crystalline Na4P2O7 and an amorphous phase were formed first from an equimolar mixture of Na2HPO4·NaH2PO4 and Na2HPO4 at temperatures above 150°C. Further heating resulted in the formation of Na5P3O10-I (high-temperature form) at the expense of the crystalline Na4P4O7 and amorphous phase. Crystalline Na5P3O10-II (low-temperature form) appears after Na5P3O10-I.Conditions which affect the yield of crystalline Na4P2O7 and amorphous phase as intermediates and their effect on the yield of Na5P3O10 are also presented.


2021 ◽  
pp. 174751982098472
Author(s):  
Lalmi Khier ◽  
Lakel Abdelghani ◽  
Belahssen Okba ◽  
Djamel Maouche ◽  
Lakel Said

Kaolin M1 and M2 studied by X-ray diffraction focus on the mullite phase, which is the main phase present in both products. The Williamson–Hall and Warren–Averbach methods for determining the crystallite size and microstrains of integral breadth β are calculated by the FullProf program. The integral breadth ( β) is a mixture resulting from the microstrains and size effect, so this should be taken into account during the calculation. The Williamson–Hall chart determines whether the sample is affected by grain size or microstrain. It appears very clearly that the principal phase of the various sintered kaolins, mullite, is free from internal microstrains. It is the case of the mixtures fritted at low temperature (1200 °C) during 1 h and also the case of the mixtures of the type chamotte cooks with 1350 °C during very long times (several weeks). This result is very significant as it gives an element of explanation to a very significant quality of mullite: its mechanical resistance during uses at high temperature remains.


Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1042
Author(s):  
Xavier H. Guichard ◽  
Francesco Bernasconi ◽  
Alessandro Lauria

Effective charge compensation of europium in hafnium oxide nanoparticles was achieved at low temperature, allowing high doping incorporation (up to 6 at.%) and enhanced luminescence. The efficiency of the incorporation and charge compensation was confirmed by scanning electron microscope energy dispersive X-ray spectroscopy and powder X-ray diffraction measurements. Despite the known polymorphism of hafnium oxide, when doped to a concentration above 3 at.%, only the pure monoclinic phase was observed up to 6 at.% of europium. Furthermore, the low-temperature solvothermal route allowed the direct formation of stable dispersions of the synthesized material over a wide range of concentrations in aqueous media. The dispersions were studied by diffuse light scattering (DLS) to evaluate their quality and by photoluminescence to investigate the incorporation of the dopants into the lattice.


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