X‐Ray Diffraction Studies of Aqueous Alkaline‐Earth Chloride Solutions

1972 ◽  
Vol 56 (8) ◽  
pp. 3783-3786 ◽  
Author(s):  
James N. Albright
1998 ◽  
Vol 224 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Uwe Hoppe ◽  
Günter Walter ◽  
Rainer Kranold ◽  
Dörte Stachel ◽  
Andrea Barz

2018 ◽  
Vol 74 (5) ◽  
pp. 623-627 ◽  
Author(s):  
Sviatoslav Baranets ◽  
Hua He ◽  
Svilen Bobev

Three isostructural transition-metal arsenides and germanides, namely niobium nickel arsenide, Nb0.92(1)NiAs, niobium cobalt arsenide, NbCoAs, and niobium nickel germanide, NbNiGe, were obtained as inadvertent side products of high-temperature reactions in sealed niobium containers. In addition to reporting for the very first time the structures of the title compounds, refined from single-crystal X-ray diffraction data, this article also serves as a reminder that niobium containers may not be suitable for the synthesis of ternary arsenides and germanides by traditional high-temperature reactions. Synthetic work involving alkali or alkaline-earth metals, transition or early post-transition metals, and elements from groups 14 or 15 under such conditions may yield Nb-containing products, which at times could be the major products of such reactions.


1962 ◽  
Vol 6 ◽  
pp. 185-190
Author(s):  
Paul Lublin

AbstractArt X-ray diffraction study has been conducted on the emissive coating (Ba, Sr, CaO) of experimental diodes from which thermionic emission data were taken before X-ray analysis. The tubes were then opened and the oxide protected by special techniques in order to prevent the formation of the hydroxide. In addition to X-ray diffraction, other techniques were used to give a complete description of the structures present.


Author(s):  
Oleg V. Grechin ◽  
Pavel R. Smirnov

At the X-ray diffraction analysis of high concentrated aqueous electrolyte solutions with multiply charged cations small angle maxima or pre-peaks are arising on scattering intensity curves (IC) (at about 1 Å). Their existence is connected with structural appearance so called “intermediate-range order”. Previously for explanation of this phenomenon some not completely correct hypotheses were suggested. On the example of raw X-ray diffraction data of some aqueous electrolyte solutions in wide concentration range collected by using MoKα-radiation the dynamic of small angle maxima shape change has been studied. It has been noted that pre-peaks absence on IC of cesium iodide and chloride solutions is not supporting the hypothesis about pure small angle contribution from “heavy” ions [1, 2]. In the case of Al3+, Sc3+, Fe3+ chloride solutions relative similarity of IC shapes has been noted for solutions with similar concentrations. The common tendency of pre-peaks position and intensity change has also been followed up. At the same time at comparing of saturated neodymium and ytterbium chloride and bromide solutions IC unexpectable pre-peaks position relative shift for bromide solutions to the long range distance comparing with chloride solutions has also been noted. These observations do not find complete agreement with hypothesis on realization in the structure mainly inter cationic distances [3, 4] and on existence in solutions “liquid type quasi-close-packing for cations” [5, 6]. On the basis of mainly realistic explanation of the pre-peak appearance reason from [7] the authors of this paper propose their own version. Noted shift of pre-peak position with concentration decreasing has been made in accordance with consideration described earlier for lanthanide solutions [8, 9]. The conclusion about pre-peaks on IC arising nature is conditioned by ordered interionic distribution which depends not only on ionic nature but also on solution concentration. For high concentrated solutions with considerable solvent deficit the quasi-periodic inter complex distribution has been supposed. The composition of structure determined cationic complexes has also been discussed. The diluted aqueous electrolyte solutions structure is determined by simple cationic and anionic complexes equidistant distribution.


Author(s):  
G. Nagelschmidt

Unpublished work carried out in this laboratory several years ago had shown that the first-order basal X-ray reflections of illite from South Wales occurred at a spacing of about 10Å both with potassium- and calcium-saturated samples. Recently Jackson and others observed that hydrated mica samples having a 10Å basal spacing when saturated with potassium, showed a 12 to 13Å. spacing after saturation with calcium. They interpreted their results by ascribing to illite a limited capacity for reversible lattice shrinkage and expansion, identical in type with that known for montmorillonite.In order to study the problem further three illite and two glauconite samples were treated with concentrated calcium chloride solutions for five weeks under frequent renewal of the solution.


2015 ◽  
Vol 670 ◽  
pp. 95-100 ◽  
Author(s):  
Lyudmila N. Mishenina ◽  
Liliya A. Selyunina ◽  
Tatiana M. Botvina

Alkaline earth metal aluminates activated by rare-earth ions (REn+) possess intensive luminescence upon UV excitation. The paper studies phase formation of calcium aluminate prepared by the sol-gel method. The stages of the end products’ formation using methods of the thermal and the infrared spectrometric analysis and X-ray diffraction are proposed. Dependence of phase composition, the surface morphology and luminescence properties on the annealing temperature of the precursor is investigated.


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