X-Ray Diffraction Studies of Systems Involved in the Preparation of Alkaline Earth Sulfide and Selenide Phosphors1

1948 ◽  
Vol 70 (6) ◽  
pp. 2043-2046 ◽  
Author(s):  
William Primak ◽  
Herman Kaufman ◽  
Roland Ward
Keyword(s):  
Alkaline Earth ◽  
X Ray Diffraction ◽  
X Ray

X-ray diffraction study on the mixed alkalialkaline earth effect in Ba, Na metaphosphate glasses

1998 ◽  
Vol 224 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Uwe Hoppe ◽  
Günter Walter ◽  
Rainer Kranold ◽  
Dörte Stachel ◽  
Andrea Barz
Keyword(s):  
Diffraction Study ◽  
Alkaline Earth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mixed Alkali

Niobium-bearing arsenides and germanides from elemental mixtures not involving niobium: a new twist to an old problem in solid-state synthesis

2018 ◽  
Vol 74 (5) ◽  
pp. 623-627 ◽  
Author(s):  
Sviatoslav Baranets ◽  
Hua He ◽  
Svilen Bobev
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Diffraction Data ◽  
Alkaline Earth ◽  
Alkaline Earth Metals ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Temperature Reactions ◽  
First Time ◽  
Synthetic Work

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.

An X-Ray Study of the Structure of the Alkaline Earth Oxide Cathode

1962 ◽  
Vol 6 ◽  
pp. 185-190
Author(s):  
Paul Lublin
Keyword(s):  
Diffraction Study ◽  
Alkaline Earth ◽  
Thermionic Emission ◽  
X Ray Diffraction ◽  
Emission Data ◽  
Alkaline Earth Oxide ◽  
X Ray ◽  
Oxide Cathode

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.

Synthesis and Characteristics of CaAl2O4:Eu3+ Phosphor Prepared by Zol-Gel Method

2015 ◽  
Vol 670 ◽  
pp. 95-100 ◽  
Author(s):  
Lyudmila N. Mishenina ◽  
Liliya A. Selyunina ◽  
Tatiana M. Botvina
Keyword(s):  
Alkaline Earth ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Earth Metal ◽  
Rare Earth Ions ◽  
Spectrometric Analysis ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Uv Excitation

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.

A novel alkaline earth strontium(II) coordination polymer: poly[hexaaquatetrakis(μ5-pyridine-2,6-dicarboxylato)bis(μ4-pyridine-2,6-dicarboxylato)(μ7-sulfato)heptastrontium(II)]

2014 ◽  
Vol 70 (6) ◽  
pp. 584-587 ◽  
Author(s):  
Wei Zhang ◽  
Shu-Guang Qi ◽  
Yu-Quan Feng
Keyword(s):  
Coordination Polymer ◽  
Coordination Mode ◽  
Alkaline Earth ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Water Molecules ◽  
Stacking Interactions ◽  
X Ray Diffraction ◽  
Sulfate Anion ◽  
X Ray

The title compound, [Sr7(C7H3NO4)6(SO4)(H2O)6]n, has been synthesized by an ionothermal method using the ionic liquid 1-ethyl-3-methylimidazolium ([Emim]Br) as solvent, and characterized by elemental analysis, energy-dispersive X-ray spectroscopy, IR and single-crystal X-ray diffraction. The structure of the compound can be viewed as a three-dimensional coordination polymer composed of Sr2+cations, pyridine-2,6-dicarboxylate anions, sulfate anions and water molecules. The compound not only exhibits a three-dimensional structure with a unique coordination mode of the sulfate anion, but also features the first example of a heptanuclear strontium(II) coordination polymer. The structure is further stabilized by O—H...O hydrogen bonds and π–π stacking interactions.

scholarly journals TAILORING THE MICROWAVE DIELECTRIC PROPERTIES OF ALKALINE EARTH GEHLENITE TYPE CERAMIC

2013 ◽  
Vol 22 ◽  
pp. 173-178 ◽  
Author(s):  
B. ARUN ◽  
K. M. MANU ◽  
M. T. SEBASTIAN
Keyword(s):  
Dielectric Properties ◽  
Alkaline Earth ◽  
Microwave Dielectric Properties ◽  
Partial Substitution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Isovalent Substitution ◽  
Microwave Dielectric ◽  
Low Permittivity ◽  
Zinc Borosilicate

The effect of glass fluxing and isovalent substitution on the microwave dielectric properties of low permittivity Sr 2 Al 2 SiO 7 (SAS) ceramic has been investigated. X – ray diffraction pattern of all the compositions indicate the formation of tetragonal Gehlenite type ceramics with space group [Formula: see text] (no. 113). The addition of small amounts of lithium magnesium zinc borosilicate (LMZBS) glass to Sr 2 Al 2 SiO 7 ceramic enhanced the densification. Glass fluxing also improved the quality factor and relative permittivity. A small partial substitution of Al 3+ and Si 4+ by Ga 3+ and Ge 4+ was found to degrade the dielectric properties of SAS ceramic. The composition Sr 2 Al 2 SiO 7 + 1 wt. % LMZBS glass showed the best dielectric properties with εr = 7.3, Qu×f = 36000 GHz and τf = −23.0 ppm/°C.

Two novel alkaline earth coordination polymers constructed from cinnamic acid and 1,10-phenanthroline: synthesis and structural and thermal properties

2018 ◽  
Vol 74 (2) ◽  
pp. 240-247 ◽  
Author(s):  
Nassima Bendjellal ◽  
Chahrazed Trifa ◽  
Sofiane Bouacida ◽  
Chaouki Boudaren ◽  
Mhamed Boudraa ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Coordination Polymers ◽  
Crystal Engineering ◽  
Alkaline Earth ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Carboxylate Groups ◽  
A Chain

In coordination chemistry and crystal engineering, many factors influence the construction of coordination polymers and the final frameworks depend greatly on the organic ligands used. The diverse coordination modes of N-donor ligands have been employed to assemble metal–organic frameworks. Carboxylic acid ligands can deprotonate completely or partially when bonding to metal ions and can also act as donors or acceptors of hydrogen bonds; they are thus good candidates for the construction of supramolecular architectures. We synthesized under reflux or hydrothermal conditions two new alkaline earth(II) complexes, namely poly[(1,10-phenanthroline-κ2N,N′)bis(μ-3-phenylprop-2-enoato-κ3O,O′:O)calcium(II)], [Ca(C10H7O2)2(C10H8N2)]n, (1), and poly[(1,10-phenanthroline-κ2N,N′)(μ3-3-phenylprop-2-enoato-κ4O:O,O′:O′)(μ-3-phenylprop-2-enoato-κ3O,O′:O)barium(II)], [Ba(C10H7O2)2(C10H8N2)]n, (2), and characterized them by FT–IR and UV–Vis spectroscopies, thermogravimetric analysis (TGA) and single-crystal X-ray diffraction analysis, as well as by powder X-ray diffraction (PXRD) analysis. Complex (1) features a chain topology of type 2,4 C4, where the Ca atoms are connected by O and N atoms, forming a distorted bicapped trigonal prismatic geometry. Complex (2) displays chains of topology type 2,3,5 C4, where the Ba atom is nine-coordinated by seven O atoms of bridging/chelating carboxylate groups from two cinnamate ligands and by two N atoms from one phenanthroline ligand, forming a distorted tricapped prismatic arrangement. Weak C—H...O hydrogen bonds and π–π stacking interactions between phenanthroline ligands are responsible to the formation of a supramolecular three-dimensional network. The thermal decompositions of (1) and (2) in the temperature range 297–1173 K revealed that they both decompose in three steps and transform to the corresponding metal oxide.

Lanthanum tetrazinc, LaZn4

2012 ◽  
Vol 68 (6) ◽  
pp. i37-i40 ◽  
Author(s):  
Igor Oshchapovsky ◽  
Volodymyr Pavlyuk ◽  
Grygoriy Dmytriv ◽  
Alexandra Griffin
Keyword(s):  
Rare Earth ◽  
Diffraction Data ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Structure Type ◽  
Alkaline Earth Metal ◽  
X Ray Diffraction ◽  
X Ray ◽  
A Site ◽  
First Time

The structure of lanthanum tetrazinc, LaZn4, has been determined from single-crystal X-ray diffraction data for the first time, approximately 70 years after its discovery. The compound exhibits a new structure type in the space groupCmcm, with one La atom and two Zn atoms occupying sites withm2msymmetry, and one Zn atom occupying a site with 2.. symmetry. The structure is closely related to the BaAl4, La3Al11, BaNi2Si2and CaCu5structure types, which can be presented as close-packed arrangements of 18-vertex clusters, in this case LaZn18. The kindred structure types contain related 18-vertex clusters around atoms of the rare earth or alkaline earth metal.

Crystal Structures and Thermal Behavior of Alkaline Earth Tricyanomethanides

2008 ◽  
Vol 63 (3) ◽  
pp. 285-288 ◽  
Author(s):  
Karl E. Bessler ◽  
Claudia C. Gatto ◽  
Lincoln L. Romualdo ◽  
Javier A. Ellena ◽  
Maria J. de A. Sales
Keyword(s):  
Crystal Structure ◽  
Coordination Polymer ◽  
Thermal Behavior ◽  
Crystal Structures ◽  
Alkaline Earth ◽  
Three Dimensional ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Interpenetrating Networks ◽  
X Ray

The alkaline earth tricyanomethanides Mg(tcm)2 · 2H2O, Ca(tcm)2, Sr(tcm)2 ・H2O and Ba(tcm)2 · 2H2O were prepared from aqueous solutions of the respective chlorides and silver tricyanomethanide. Their IR spectra and thermal behavior are described. The crystal structures of Ca(tcm)2 and Ba(tcm)2 · 2H2O were determined by single crystal X-ray diffraction. The structure of Ca(tcm)2 is of the type found for several transition metal tricyanomethanides [1], containing two independent interpenetrating networks. Ba(tcm)2 · 2H2O has a unique crystal structure corresponding to a three-dimensional coordination polymer with nine fold coordinated Ba atoms connected by water molecules and tricyanomethanide anions.

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