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Rare-earth based OLEDs
TG-FTIR thermal stability investigation of tetrakis beta-diketonates complexes
well suitable for display applications. Pure red, green, and blue emissions are required, and in this context, rare-earth (RE)-based complexes are interesting candidates to be used for this purpose [ 3 – 5 ]. Due to the intra f–f transitions of
Abstract
Rare earth complexes ofm-nitrobenzoic acid (LnL3·2H2O,Ln=La-Lu and Y, except Pm, HL=m-nitrobenzoic acid) were synthesized and characterized by elemental analysis, chemical analysis, IR spectroscopy and X-ray diffraction analysis. The dehydration behaviour of these complexes was studied in detail by means of TG-DTA and DSC. Dehydration occurs over the temperature range 76–215°C, and the temperature of formation of the anhydrous complexes decreases with increasing atomic number of the rare earth. The activation energies and enthalpy changes for te dehydration were obtained.
Barium bromate decomposes in the solid state through various stages: (i) initial gas evolution, (ii) induction period, (iii) slow linear reaction, (iv) acceleratory and decay stages. Rare earth semiconductors (p-type), Gd2O3 and Dy3O3 facilitate the acceleratory and decay stages without affecting the induction and linear periods. The extent of decomposition is higher in the case of mixture than that of the pure salt. The data are discussed in the light of theories of Prout—Tompkins and Avarami-Erofeev mechanisms exploring that nucleation occurs in a chain branching manner and there is two dimensional growth of nuclei.
Abstract
By using a DSK of the French firm Seteram, the standard enthalpies of formation of 5 tellurites and 5 tetratellurites of the rare earths Gd, Tb, Dy, Tm and Yb were determined for the first time. Three parallel determinations for each sample were compared. The results are very similar, which is an indication of the great reliability of the method used and the correctness of the data obtained.
2151 2153 M.-B. Park et al., Effect of rare earth ions-doping on the chemical and optical features of nano-crystalline (Er, Tb) Si thin films, Applied Surface Science, B234, 78
Abstract
The combination of neutron activation analysis (NAA) and electrochemistry has been used to study the deposition behavior of rare earth elements, as it is reported that excepting La, no other rare earths are electrodeposited. The radiotracers of rare earth elements were electrolyzed in an aqueous medium on a graphite electrode by varying the voltage and time of electrodeposition, thereby optimizing the final experimental conditions for quantitative deposition of rare earth elements. The observations are reported in this work.
Abstract
Hydrochemical, environmental isotope and injected radiotracer investigations were carried out in order to investigate the possible source of contaminants and their movement in groundwater at Indian Rare Earths (IRE) site. Water samples were collected from piezometers, dug wells and river in and around IRE site for measurement of physical parameters, chemistry and isotopes. Chemical results show high fluoride, nitrate, sulphate and phosphate concentrations in piezometers whereas dug wells and river samples are free from contamination. Isotope data indicate that the contaminated groundwaters are enriched in δ2H and δ18O compared to dug well and river samples. Radiotracer experiments were carried out using single-well and multi-well techniques (radiotracers: 82Br and 3H) for determining groundwater filtration velocity and flow direction, respectively. Groundwater filtration velocity was found to be about 1.3 cm/day and flow direction is from south to north. Based on the investigations it can be concluded that groundwater is getting contamination from southern part of IRE campus and the possible source for these contaminants could be the Fertilizer and Chemical of Travancore (FACT) industry.
Introduction The rare earth (RE) elements play an important role in many fields of advanced materials science. Waste RE polishing powder is failure or unqualified product during its application and production. The content of
, affecting subsequent dynamic aging [ 14 ]. In recent studies, the addition of rare earth has been considered an effective microstructure modifier to improve the mechanical properties of aluminum alloys. Primary research with these materials has focused on Al
obtain the soluble form of the ligand. Ammonium salt of the acid was added to an aqueous solution of lanthanide chloride while stirring. For the preparation of the complexes, the following oxides of rare earth elements were used: La 2 O 3 , Pr 6 O 11 , Nd
