ChemInform Abstract: Hydrothermal Synthesis, Crystal Structure, and Superconductivity of a Double-Perovskite Bi Oxide.

The effect of microwave radiation on the hydrothermal synthesis of the double perovskite Sr2FeMoO6 has been studied based on a comparison of the particle size and structural characteristics of products from both methods. A temperature, pressure, and pH condition screening was performed, and the most representative results of these are herein presented and discussed. Radiation of microwaves in the hydrothermal synthesis method led to a decrease in crystallite size, which is an effect from the reaction temperature. The particle size ranged from 378 to 318 nm when pH was 4.5 and pressure was kept under 40 bars. According to X-ray diffraction (XRD) results coupled with the size-strain plot method, the product obtained by both synthesis methods (with and without microwave radiation) have similar crystal purity. The Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) techniques showed that the morphology and the distribution of metal ions are uniform. The Curie temperature obtained by thermogravimetric analysis indicates that, in the presence of microwaves, the value was higher with respect to traditional synthesis from 335 K to 342.5 K. Consequently, microwave radiation enhances the diffusion and nucleation process of ionic precursors during the synthesis, which promotes a uniform heating in the reaction mixture leading to a reduction in the particle size, but keeping good crystallinity of the double perovskite. Precursor phases and the final purity of the Sr2FeMoO6 powder can be controlled via hydrothermal microwave heating on the first stages of the Sol-Gel method.

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Hydrothermal Synthesis and X-ray Crystal Structure of Four Inorganic-Organic Hybrid Compounds in Vanadium /Copper Iodate Family

Zeitschrift für anorganische und allgemeine Chemie ◽

10.1002/zaac.200800085 ◽

2008 ◽

Vol 634 (9) ◽

pp. 1601-1607

Author(s):

Xiaomin Liu ◽

Guanghua Li ◽

Minghui Bi ◽

Yawei Hu ◽

Yang Yu ◽

...

Keyword(s):

Crystal Structure ◽

Hydrothermal Synthesis ◽

X Ray ◽

Organic Hybrid ◽

Hybrid Compounds

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The first proof of protonated anion tetrahedra in the tsumcorite-type compounds

Mineralogical Magazine ◽

10.1180/0026461046850217 ◽

2004 ◽

Vol 68 (5) ◽

pp. 757-767 ◽

Cited By ~ 4

Author(s):

T. Mihajlović ◽

H. Effenberger

Keyword(s):

Crystal Structure ◽

Hydrothermal Synthesis ◽

Single Crystal ◽

Diffraction Data ◽

Title Compound ◽

Monoclinic Space Group ◽

X Ray Diffraction ◽

Hydrogen Atoms ◽

Synthetic Compounds ◽

X Ray

AbstractHydrothermal synthesis produced the new compound SrCo2(AsO4)(AsO3OH)(OH)(H2O). The compound belongs to the tsumcorite group (natural and synthetic compounds with the general formula M(1)M(2)2(XO4)2(H2O,OH)2; M(1)1+,2+,3+ = Na, K, Rb, Ag, NH4, Ca, Pb, Bi, Tl; M(2)2+,3+ = Al, Mn3+, Fe3+, Co, Ni, Cu, Zn; and X5+,6+ = P, As, V, S, Se, Mo). It represents (1) the first Sr member, (2) the until now unknown [7]-coordination for the M(1) position, (3) the first proof of (partially) protonated arsenate groups in this group of compounds, and (4) a new structure variant.The crystal structure of the title compound was determined using single-crystal X-ray diffraction data. The compound is monoclinic, space group P21/a, with a = 9.139(2), b = 12.829(3), c = 7.522(2) Å, β = 114.33(3)°, V = 803.6(3) Å3, Z = 4 [wR2 = 0.065 for 3530 unique reflections]. The hydrogen atoms were located experimentally.

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