- The effect of doping on the thermal decomposition of strontium bromate
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The thermal decomposition of strontium bromate doped with KBrO3, Mg(BrO3)2, Al(BrO3)3 and KBr (10**-4 to 10**-1 M), was studied by dynamic thermogravimetry and the kinetic parameters were computed using the Coats-Redfern and Horowitz-Metzger equations. Do
- Nair, S. M. K.,Sahish, T. S.
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- New SrPb3Br8 crystals: Growth, crystal structure and optical properties
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SrBr2-PbBr2 system was investigated. A new compound of SrPb3Br8 was obtained and investigated by powder and single crystal XRD and spectroscopic methods. SrPb3Br8 crystals have orthorhombic symmetry with Pnma space group, a = 8.0056 (4) ?, b = 4.7359 (2) ?, c = 9.5208 (5) ?. These crystals are transparent from ≈360 nm, the band gap is 3.20 eV and calculated density is 6.242 g/cm3. Electronic structure of SrPb3Br8 was elucidated based on data of X-ray photoelectron spectroscopy (XPS) and X-ray emission spectroscopy (XES). In particular, XPS core-level and valence-band spectra were measured for pristine and Ar+ ion-irradiated surfaces of SrPb3Br8 crystals. The XPS results reveal high hygroscopicity of the SrPb3Br8 single crystal surface. Comparison on a common energy scale of the XPS valence-band spectrum of SrPb3Br8 the XES Br Kβ2 band representing the energy distribution of the Br 4p states in this bromide indicate that the principle contributions of the Br 4p states occur in the upper portion of the valence band, with also their significant contributions in other valence-band portions.
- Isaenko, Ludmila I.,Goloshumova, Alina A.,Yelisseyev, Alexander P.,Shubin, Yuri V.,Khyzhun,Naumov, Dmitrii Yu.,Tarasova, Alexandra Yu.
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- Synthesis and structural characterization of new phases in the cubic M 3Te2O6X2 (M = Sr, Ba; X = Cl, Br) structure family
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Four alkaline earth oxotellurate(IV) halides with common formula M 3Te2O6X2 (M = Sr, Ba; X = Cl, Br) have been prepared as polycrystalline powders and/or in the form of single crystals. All compounds crystallize in the cubic space group Fd (3) m with cell parameters a = 15.9351(4) A for Sr3Te2O 6Cl2 (single-crystal X-ray data), 16.052(5) A for Sr3Te2O6Br2 (powder X-ray data), 16.688(2) A for Ba3Te2O6Cl2 (single-crystal X-ray data) and 16.8072(3) A for Ba3Te 2O6Br1.64Cl0.36 (single-crystal X-ray data). The results of the crystal structure analyses reveal a rigid (3)[M3Te2O6]2+ framework which can be described as being composed of regular octahedra of two types of chemically non-bonded M6 octahedra that are capped by trigonal pyramidal [TeO3] anions located above every second face of one of the M 6 octahedra. The halide X- anions are situated in the voids of the [M3Te2O6]2+ framework. Dependent on the nature of the halogen, the anions show various kinds of occupational disorder which eventually led to a revision of the previous structure model of Ba3Te2O6Cl2. A comparative discussion with other structures of general formula M 3Ch2O6X2 (M = divalent metal; Ch = Te, Se; X = Cl, Br) is presented. Copyright
- Stoeger, Berthold,Weil, Matthias,Silich, Konstantin A.,Olenev, Andrey V.,Berdonosov, Peter S.,Dolgikh, Valery A.
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- Ammonia Absorption on Alkaline Earth Halides as Ammonia Separation and Storage Procedure
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For the low pressure ammonia synthesis (~1 MPa, 573-623 K), 40-80 kPa of ammonia produced must be separated. For this purpose, the absorption behavior of five kinds of alkaline earth metal halides (MgCl2, CaCl2, CaBr2, SrC
- Liu, Chun Yi,Aika, Ken-Ichi
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- Preparation and spectroscopic characterization of strontium and barium tetrabromoferrate(III) and the crystal structure of Ba(FeBr4)2
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The synthesis of the hitherto unknown bromoferrates(III) of alkaline-earth metals was carried out by heating mixtures of the metals or the binary bromides together with bromine at temperatures of 450 °C and pressures of up to 1500 bar in closed quartz ampoules. The attempts have been successful only with the larger cations of Sr and Ba. In the case of Be, Mg, and Ca only mixtures of the binary bromides with FeBr3 could be received. By analysis of the Raman and electronic spectra the dark red compounds of Sr and Ba have been characterized as ternary tetrabromoferrates(III) containing tetrahedral FeBr4 anions. The composition M(FeBr4)2 (M = Sr, Ba) has been determined by potentiometric and titrimetric analysis and thermal degradation by thermogravimetry. A single crystal structure determination of Ba(FeBr4)2 confirmed the spectroscopic assignments. The orthorhombic crystal structure (space group Pbca; a = 13.054(3) A; b = 11.093(2) A; c = 21.764(4) A; Z = 8) consists of FeBr4 and BaBr9 polyhedra.
- Armbruster, Markus,Rotter, Heinz W.,Thiele, Gerhard
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p. 1697 - 1700
(2008/10/08)
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- Studies on ABX6 Compounds. II[1] The BaThBr6 Structure Type
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The compounds AThBr6 (A:Ca, Sr, Ba) crystallize in an ordered substitution variant of the PuBr3 type. Their syntheses and special features of the crystal structures are described.
- Beck, H. P.,Kuehn, F.
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