Europium Sulfate Research Articles

Structural phase transitions in TlSm(SO4)2·4H2O and TlEu(SO4)2·4H2O single crystals: EPR evidence for possible role of molecular dynamics and fluctuations

Abstract EPR investigations of thallium europium sulphate tetrahydrate (TEST) and thallium samarium sulphate tetrahydrate (TSST) single crystals, using Gd3+ probe ion, reveal that they undergo phase transitions similar to those reported in isostructural ammonium compounds, although the transition temperatures are consistently lower. This implies that the phase transitions are not associated directly with NH+ 4 molecular dynamics, although it does have an influence in shifting the transition temperatures.

Adsorption Behaviour of Europium Sulphate on Different Inorganic Ion Exchangers

Potassium zinc hexacyanoferrate, zirconium titanium phosphate (ZTP) and zirconium phosphate silicate (ZPS) ion exchangers were prepared. They were used as cation exchanger to study the uptake of Eu from sulphuric acid solutions. The distribution coefficient data was used to calculate the formation constant of the Europium sulphate complex.

Thermal decomposition of Eu 2(SO 4) 3·8H 2O studied by low temperature high-resolution luminescence spectroscopy

The thermal decomposition in air at temperatures up to 1450°C of hydrated europium sulfate has been studied by high-resolution luminescence spectroscopy. X-ray powder diffraction, differential thermal analysis (DTA), and thermogravimetric analysis (TGA). Information regarding the number of europium(III) species present in a particular material can be deduced from the fine structure within the europium(III) emission bands. Determination of the site symmetry of the europium(III) emitting species can be deduced from a complete analysis of the luminescence spectra. The application of this method has shown the presence of a multitude of partially dehydrated species in materials where the more conventional thermal analysis methods predict the presence of only pure anhydrous material. The data indicate the presence of an intermediate assumed to be Eu 2O(SO 4) 2. The presence of this intermediate has been suggested before, though never actually observed. Complete decomposition to Eu 2O 2SO 4 occurs by 800°C and finally to Eu 2O 3 by 1150°C.

Thermal decomposition of Eu 2(SO 4) 3·8H 2O studied by high resolution luminescence spectroscopy

The thermal decomposition of hydrated europium sulfate was monitored by high resolution photoluminescence studies of the decomposition products. By application of the luminescence method, information can be gleaned from the fine structure within the europium(III) bands regarding the number of europium (III) species existing in the sample. In addition, some idea of the site symmetry of the emitting europium(III) species can be deduced from a detailed analysis of the spectra. Examination of the luminescence spectra revealed that dehydration of the europium(III) sulfate yields a multitude of hydrated intermediates, and these eventually form a well-defined anhydrous sulfate. Our data indicate the presence of a hitherto unsuspected intermediate Eu 2O(SO 4) 2 in the decomposition of the anhydrous Eu 2(SO 4) 3 to a well-defined Eu 2O 2SO 4 end product.

Energy States of Solids: Evidence from Thermal Data for the Existence of Low Electronic Energy Levels in Europium Ion. The Heat Capacity of Europium Sulfate Octahydrate from 60 to 300°K.

Energy States of Solids: Evidence from Thermal Data for the Existence of Low Electronic Energy Levels in Europium Ion. The Heat Capacity of Europium Sulfate Octahydrate from 60 to 300°K.

Fluorescence of Pure Salts of the Rare Earths

INVESTIGATING the connexion between the emission spectra in colourless materials1 and the absorption spectra of the ions of the rare earths2 we have found that the pure salts of the rare earths can also exhibit a fluorescence of a surprising brightness. Up to the present, this fact was still very doubtful3. Under excitation with violet and ultra-violet light, europium sulphate in particular shows a brilliant red fluorescence. Terbium sulphate fluoresces also very strongly with a pale greenish colour. The luminosity of the sulphates of samarium and dysprosium is weaker. Our samples of the sulphates of holmium and erbium showed no perceptible emission. The spectra emitted are very sharp, especially at lower temperatures.