THE COPPER VALENCE STATE AND THE STRUCTURE OF Li, Ce, Eu, V-DOPED Y-Ba-Cu-O SYSTEM

1989 ◽  
Vol 03 (12) ◽  
pp. 955-960 ◽  
Author(s):  
J.B. ZHANG ◽  
L.F. QU ◽  
K.Y. HOU ◽  
D.L. YANG ◽  
D.J. CHEN ◽  
...  

High-Tc superconductors with nominal composition of YBa 2 Cu 3 O y and Y 1−x L x Ba 2 Cu 3 O y ( L=Li , Ce, Eu, V) were synthesis by the solid state reaction of appropriate amount of Y 2 O 3, BaO or BaCO 3, Cu 2 O , CuO, and LO x. The Cu 3+/ Cu 2+ ratio was determined by Iodometric titration and oxygen content in the oxides calculated from the ratio. The crystal structure was determined by electron and powder X-ray diffraction analysis. It shows that that ratio of Cu 3+/ Cu 2+ and the crystal structure could be changed as dopping appropriate amount of metal in the Y-Ba-Cu-O system.

Author(s):  
Hongqiang Cui ◽  
Yongze Cao ◽  
Lei Zhang ◽  
Yuhang Zhang ◽  
Siying Ran ◽  
...  

Er3+ with different concentrations doped K2Yb(PO4)(MoO4) phosphors were prepared by a solid-state reaction method, and the layered orthorhombic crystal structure of the samples was confirmed by X-ray diffraction (XRD). Under...


2004 ◽  
Vol 18 (15) ◽  
pp. 2177-2183 ◽  
Author(s):  
G. ILONCA ◽  
S. PATAPIS ◽  
E. MACOCIAN ◽  
F. BEIUSAN ◽  
T. JURCUT ◽  
...  

Polycrystalline samples with a nominal composition Ru 1-x Sb x Sr 2 GdCu 2 O 8-d were prepared by a solid state reaction technique. A mixture of RuO 2, Sb 2 O 3, Gd 2 O 3, SrCO 3 and CuO was used to obtain the samples. We performed X-ray diffraction analyses, DC susceptibility and transport measurements and the studies showed that the samples were almost pure Ru -1212 phase. We also observed that Sb doping reduce the conductivity of the system and the transition temperature decreases with increasing Sb content. This may be due to a distortion of RuO 6 octahedral which is responsible for the increase of holes localization.


2016 ◽  
Vol 20 (01n04) ◽  
pp. 245-253 ◽  
Author(s):  
Hirotaka Mori ◽  
Atsuhiro Osuka

meso–meso Directly-linked trimeric and pentameric porphyrin–hexaphyrin hybrid arrays 5 and 6 comprising of electron-deficient porphyrin units were prepared by cross-condensation of monomeric and dimeric electron-deficient meso-formyl porphyrins with a tripyrrane. The solid-state structures of 5 and 6 have been determined by single crystal X-ray diffraction analysis. The latter is the largest crystal structure of meso–meso linked multiporphyrinic array analogues reported to date.


2007 ◽  
Vol 62 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Nachiappan Arumugam ◽  
Eva-Maria Peters ◽  
Martin Jansen

A new potassium molybdenum oxide, K6Mo10O33, was synthesized by solid state reaction from the appropriate quantities of pre-dried MoO3 and K2MoO4, fired at around 650 °C for 2 d. The structure has been solved by using single crystal X-ray diffraction. The compound adopts the space group P1, with the lattice constants a = 7.7100(5), b = 11.9659(8), c = 17.1321(12) A° , α = 86.42 (10), β = 77.18(10), γ = 74.14(10)°. The structure is built up of infinite chains of edge-sharing MoO6 octahedra and groups of four MoO6 octahedra forming Mo4O17 units. These sub-units are connected together by common vertices.


2020 ◽  
Author(s):  
Liang Zhang ◽  
Langping Dong ◽  
Yonghui Xu ◽  
Shuwen Yin ◽  
Hongpeng You

A variety of Bi3+-activated and Bi3+-Eu3+ codoped Y3GaO6 phosphor samples were obtained by solid-state reaction. The phase purity and crystal structure of specimens were characterized via powder X-ray diffraction (XRD)...


2011 ◽  
Vol 26 (3) ◽  
pp. 244-247
Author(s):  
N. Kumada ◽  
W. Zhang ◽  
Q. Dong ◽  
T. Mochizuki ◽  
Y. Yonesaki ◽  
...  

A new barium copper niobate, Ba4CuNb3O12, was successfully prepared by high-temperature solid-state reaction in an inert atmosphere. Rietveld-refinement analysis of the XRD data of the compound showed that it has the 8H-type hexagonal perovskite structure with space group P63/mmc (#194), a = 5.830(1) Å, c = 19.123(1) Å, and chemical composition of Ba4Cu1.84Nb2.16O12-δ.


1992 ◽  
Vol 7 (4) ◽  
pp. 219-222 ◽  
Author(s):  
A. Cuneyt Tas ◽  
Mufit Akinc

AbstractA new X-ray diffraction pattern for the compound cerium oxygen apatite, Ce4.67[SiO4]3O is suggested. The compound was prepared by the solid state reaction of the oxides, CeO2 and SiO2 and has a hexagonal crystal structure with the lattice constants a = 9.6578 Å and c = 7.1187 Å. The sample of the most recent PDF pattern 31-0336* (Visser, 1978) for this compound is believed to be contaminated with significant quantities of N owing to the fact that it was prepared by mixing Ce2O3 and Si3N4 and its very close resemblance to the pattern displayed in the PDF 33-0333 given for the cerium “nitrogen” apatite, Ce5[SiO4]3N.


2010 ◽  
Vol 93-94 ◽  
pp. 251-254 ◽  
Author(s):  
Pasinee Siriprapa ◽  
Anucha Watcharapasorn ◽  
Sukanda Jiansirisomboon

Bi4-xLaxTi3O12 (where x = 0, 0.25, 0.50, 0.75 and 1) powders and ceramics were prepared using conventional solid state reaction and sintering procedures. The calcination was carried out at 750 °C for 4 h and sintering was done at 1150 °C for 4 h. The density of all ceramics was found to be comparable regardless of La concentration. X-ray diffraction analysis showed that preferred orientation of ceramic grains was reduced with addition of La ions. This reduced preferred orientation was accompanied by a decrease in grain size. The temperature dependence of dielectric constant showed a decrease in Tc with increasing La concentration.


2013 ◽  
Vol 68 (5-6) ◽  
pp. 687-692
Author(s):  
Werner Weingärtner ◽  
Gerhard Maas

The solid-state structure of chlorido[2-(N,N,N',N'-tetramethylamidinio)ethynido]silver (3), obtained by C(sp)-metalation of N,N,N',N'-tetramethyl-propiolamidinium chloride with silver(I) oxide, has been determined by X-ray diffraction analysis. A comparison of bond lengths in the propiolamidinium moiety with those of the two genuine propiolamidinium salts 4 and 5, as well as with data for the isolated N,N,N',N'-tetramethyl-propiolamidinium cation obtained by quantum-chemical calculations, has been made. It can be concluded that complex 3 is better described as a (tetramethylamidinio) ethynyl than as a 3,3-bis(dimethylamino)allenylidene silver complex


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