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Homogeneity Range (homogeneity + range)
Selected AbstractsTernary Antimonides YbTSb (T: Ni, Pd, Pt, Cu, Ag, Au) , Synthesis, Structure, Homogeneity Ranges, and 121Sb Moessbauer Spectroscopy.CHEMINFORM, Issue 15 2003Ratikanta Mishra Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis and Crystal Structure of Mercury-Substituted Type-I Clathrates A8Hg4Sn42 (A = K, Rb, Cs)EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 4 2008Andreas Kaltzoglou Abstract The mercury-substituted type-I clathrates A8Hg4Sn42,with A = K, Rb or Cs, were obtained by fusion of the pure elements at high temperatures. The crystal structures of the compounds were refined from single-crystal X-ray diffraction data. They crystallize in the space group Pmn (No. 223), Z = 1 with a = 12.1255(4) Å for K8Hg4Sn42 (1), a = 12.1838(4) Å for Rb8Hg4Sn42 (2) and a = 12.2130(4) Å for Cs8Hg4Sn42 (3). The 3D framework of four-bonded atoms defines two types of polyhedral cages of different size that are fully occupied by the alkali-metal atoms. All three compounds are considered as formally charge-balanced Zintl phases without any homogeneity range. Differential thermal analysis (DTA) indicates that the stability of the clathrates significantly depends on the size of the encaged cations. The thermal stability of the title compounds and the binary phases A8Sn44 (A = K, Rb, Cs) is discussed. Temperature-dependent magnetic measurements for compound 3 show also the expected diamagnetic behaviour. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Phase Relations in the Na0.5Bi0.5TiO3,Li3xLa(2/3),x,(1/3),2xTiO3 SystemINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 2 2009Matja, Spreitzer The phase relations and the mechanism of solid-state synthesis for the Na0.5Bi0.5TiO3,Li3xLa(2/3),x,(1/3),2xTiO3 system were investigated using X-ray powder diffraction, scanning electron microscopy, and thermal analysis. The study revealed that the extent of the homogeneity range,which is related to the A-site substitution between (Na0.5Bi0.5)2+ and (Li3xLa(2/3),x,(1/3),2x)2+ pseudo cations of a perovskite structure,depends strongly on the ordering of the (Li3xLa(2/3),x,(1/3),2x)2+ species. The solid-state reaction of the compounds in the homogeneity range is completed only after multiple high-temperature firings. However, the system is also subjected to a slow thermal decomposition; this is particularly so for the compounds with a high × value and an increased Li3xLa(2/3),x,(1/3),2xTiO3 concentration. [source] High-Temperature Ferromagnetism and Tunable Semiconductivity of (Ba, Sr)M2,±,xRu4,,,xO11 (M,=,Fe, Co): A New Paradigm for Spintronics,ADVANCED MATERIALS, Issue 7 2008Larysa Shlyk Ternary ruthenium ferrites (Ba,Sr)Fe2,±,xRu4,,,xO11 exhibit long-range ferromagnetic order well above room temperature along with favorable narrow- gap semiconducting properties. Electronic structure and physical properties can be tuned by simple chemical substitution of two elements, Fe and Co, or by varying the relative concentration of 3d and 4d elements within the homogeneity range. These promising properties within a single structural family open up a host of potential device applications. [source] Formation Kinetics of a Bi3Nb1,xTaxO7 Fluorite-Type Solid Solution and Thermodynamic Stability of the Bi3TaO7 End MemberJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 9 2010Ursa Pirnat Analysis of kinetic characteristics of the incommensurate,commensurate transformation in the Bi3Nb1,xTaxO7 system with a fluorite-like crystal structure enabled us to define the compositional and thermal stability ranges of the commensurate tetragonal polymorph. We showed that the tetragonal polymorph across the entire homogeneity range is isostructural to the Bi3NbO7 end member. The kinetics of the transformation from the cubic incommensurate to the tetragonal commensurate phase decreases with an increase in Ta concentration within the Bi3Nb1,xTaxO7 system. The formation studies indicate that the tetragonal Bi3TaO7 is thermodynamically stable; however, its formation via the metastable incommensurate-cubic phase is suppressed. [source] Phase Relations and Thermal Expansion Studies in the Ceria,Yttria SystemJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 10 2004Sandeep V. Chavan The synthesis, characterization, and bulk and lattice thermal expansions of a series of compounds with general composition Ce1,xYxO2,x/2 (0.0 ,x, 1.0) are reported. The XRD pattern of each product was refined to learn the solid solubility limit and the homogeneity range. The solid solubility limit of YO1.5 in CeO2 lattice, under the conditions of slow cooling from 1400°C, is represented as Ce0.55Y0.45O1.775 (i.e., 45 mol% of YO1.5). The subsequent compositions were biphase. There was no solubility of CeO2 into the lattice of YO1.5. The bulk thermal expansion measurements from ambient to 1123 K, as investigated using a dilatometer, revealed that the ,l (293,1123 K) values, within the homogeneity range, decreased on increased Y3+ content. A similar trend was observed for average lattice thermal expansion coefficient, ,a (293,1473 K), as investigated using high-temperature XRD. No ordered phases were obtained in this system under the used conditions. These studies on Ce1,xYxO2,x/2 (0.0 ,x, 1.0) system can be used to simulate the phase relation and thermal expansion behavior of Pu1,xYxO2,x/2 (0.0 ,x, 1.0), because CeO2 is widely used as a surrogate material for PuO2. [source] | |||||||||||||