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The thermal properties of cyanatocopper complexes with pyridine, bipyridine and phenanthroline are described in this paper. It was found that the thermal stabilities of the complexes were found to increase in the order py≪bipy<phen ligands. The significantly higher thermal stability of the complexes with bipyridine and phenanthroline is caused by the presence of dimeric structural units in the crystal structure and intermolecular interactions of the cyanate and heterocyclic ligands.

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Abstract  

ZnS(1-x)MSx(x=0.01 and M=Mn2+, Cu2+ and Eu2+) compounds have been obtained by precipitation from homogeneous solutions of zinc, copper, manganese and europium salts, with S2- as the precipitating anion, formed by the decomposition of thioacetamide. The thermal study of the milled zinc acetate, thioacetamide, copper acetate, manganese acetate and europium nitrate, respectively, was studied for thermal analyis TG/DSC. XRD respect exhibits a zinc blend crystal structure.

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Journal of Thermal Analysis and Calorimetry
Authors: C. Beauger, P. Grosseau, B. Guilhot, D. Huguenin, and P. Iacconi

Abstract  

The dependence of the firing conditions on the crystal structure formation of ZnGa2 O4 has been investigated. The effects of temperature and atmosphere were examined and gave evidence of the instability of the zinc gallate under a reducing atmosphere at temperatures above 600C. A new preparation route has allowed to synthesize ZnGa2 O4 at low-temperature, right from 300C, avoiding the decomposition of the matrix during the annealing.

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Thermal decomposition of borax has been researched by thermal, XRD and FTIR methods as well as SEM microscopy. Study have revealed that it proceeds according to the mechanism of internal reactions in the structure of the precursor as a medium. The following stages of the process have been distinguished: (1) dehydration, (2) internal structure reconstitution—formation of tincalconite, (3) amorphization of crystal structure, (4) gradual dehydroxylation and crystallization of Na2O2B2O3 inside the amorphous matrix.

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The results of theoretical analysis of the properties of crystal structure and bonding in relation to thermal decomposition process in chosen anhydrous metal oxalates (Cd, Co, Zn) are presented. The methods used in this analysis — the Bader’s quantum theory of atoms in molecules and bond order model (as defined by Cioslowski and Mixon), applied to topological properties of the electron density, obtained from DFT calculations performed by Wien2k package (full potential linearized augmented plane wave method), as well as Brown’s bond valence model (bonds valences and strengths, and bond and crystal strains, calculated from crystal structure and bonds lengths data) are described. Presented results allow us to state, that these methods, when used simultaneously, make possible the description and analysis of the crystal structure and bonding properties and give us the additional insight into its behavior during thermal decomposition process. The proposed theoretical approach can be considered as promising and reliable tool for theoretical analysis, allowing explanation and prediction of the properties of the structure and bonding and hence the most probable way of thermal decomposition process to take place in such structure.

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Abstract  

It has been shown that cesium oxoferrate (VI) decomposes in oxygen at 500 °C giving solid CsxFeIVO2+0.5x (x1.0). The oxidation state of iron has been confirmed by Mössbauer spectroscopy data (single symmetrical resonance line with LW=0.4 (1) mm s–1 and isomr shift of 0.15 (2) mm s–1). Cesium oxoferrate (IV), CsxFeO2+0.5x, crystallizes in the face-centered cubic system with the lattice parameter of a=8.36–8.46 Å and has a crystal structure derived from perovskite.

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Abstract  

The original investigations of ferrocene mesogens with general formula Fe(C5H4C(CH3)=N–N=CHC6H4COOC6H4OCnH2n+1J2 and their solutions in liquid crystalline solvents by Mossbauer spectroscopy as well as by calorimetry, thermomicroscopic and X-ray analysis are discussed. The data on electron, molecular and crystal structures, polymorphism and dynamical properties of these substences and frozen solutions are presented. For ferrocene mesogens and their solutions, aligned by external magnetic field, the values of order parameter and inter- and intramolecular contributions to the nuclear vibrational anisotropy of central metal atom are estimated.

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Abstract  

The Mössbauer parameters were determined on a series of catalyst mixtures of iron and zinc oxides with variable quantities of zinc. From these results, a change in the crystal structure of the iron oxide when introducing zinc into the samples was observed. The corundum structure of the -Fe2O3 phase was transformed into the spinel type of zinc ferrite when zinc oxide was present in any quantity. By means of these parameters a strong electronic interaction between the zinc ferrite and the zinc oxide present in excess was evident. The catalysts were analyzed using X-ray fluorescence /XRF/ and X-ray diffraction /XRD/.

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Abstract  

Effects of fission (fragment) damage on the magnetic properties were investigated for some uranium compounds with NaCl-type crystal structure, such as uranium monocarbide (UC, paramagnetic) monophosphide (UP, antiferro) and monosulfide (US, ferro). The induced changes in the magnetic properties due to the fission damage were much pronounced in the magnetically ordered state. A shift of the magnetic transition point (either the Neel (TN) and Curie (TC) temperature) was observed, together with the changes of the magnetic parameters. In some cases, a new magnetically ordered phase was revealed by the fission damage even at room temperature irradiation.

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Abstract  

New lanthanoid-iron complexes having phenanthlorine as the chelating ligand were synthesized and characterized by151Eu- and57Fe-Mössbauer spectroscopy. The temperature dependence of the area intensity of Mössbauer lines of europium complexes (single crystals) has been correlated to the state of molecular association in the solid state. The crystal structure of europium complex, {[Eu(phen)2(H2O)2][(μ-NC)2 Fe(CN)4]·2phen]}x was determined by X-ray crystal analysis. This complex consists of one-dimensional zig-zag chain structure.

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