Coating Carbon Nanotubes with Europium Oxide

Carbon nanotubes (CNTS) coating with europium oxide by a simple method is reported in this letter for the first time. The CNTS were refluxed in a solution of nitric acid containing europium nitrate, and the pH value was subsequently ajusted with ammonia solution. At last, the mixture was filtered and annealed. The TEM micrograph showed that the CNTS were covered with a uniform thin layer with thickness of about 15 nm. The XRD results revealed that the CNTS were coated with europium oxide.

Direct Determination of Rare Earth Impurities in High Purity Europium Oxide by ICP-MS

A novel inductively coupled plasma mass spectrometry method for direct determination of trace rare earth impurities in high purity europium oxide (Eu_2O_3) was developed. The spectral interference,matrix effect,instrument parameters fluctuation were investigated and the optimized experimental conditions were established. Under the selected conditions,the detection limits of the method are 3～7 ng·L (-1),the RSD is varied between 2.1%～8.4%,and the percentage recovery is ranged from 90% to 113% for the analytes. The solid detection limit for gross amount of 13 rare earth impurities is 0.19 μg·g (-1) when the matrix (Eu) concentration of 0.1 mg·ml (-1) was chosen. Compared with the reported methods in the literature,this method has several attractive features: simple,small sample amount required,no internal standard and matrix matching requirements.

Solid-state Syntheses, Crystal Chemistry and Optical Properties of Two Europium Oxide/sulfide Silicates, Eu2O(SiO4) and Eu5S(SiO4)3

Two europium oxide/sulfide silicates, Eu2O（SiO4） （1） and Eu5S（SiO4）3 （2）, have been synthesized using high-temperature solid-state reactions. 1 crystallizes in the monoclinic space group P21/c with a = 9.1459（7）, b = 7.1280（5）, c = 6.7655（5） ？ and ？ = 107.611（2）, belonging to the Gd2O（SiO4） structure type; 2 crystallizes in space group P63/m of the hexagonal system with a = 9.786（4） and c = 6.789（3） , belonging to the apatite Ca5Cl（PO4）3 structure type. The structure chemistry of related RE2O（SiO4） and RE5S（SiO4）3 compounds is also discussed. The optical energy gap of 2 is determined to be 2.05 eV.

Synthesis of nanosize europium oxide particles by using W/O microemulsion

Europium hydroxide particles with an average diameter of 10 run and a BET surface area of 127 m2 /g have been prepared by controlled precipitation in the polyoxyethylene octylphenol (Triton X-100) (hex-anol)/cyclohexane/water microemulsion system. After calcination in air at 750℃, the obtained europium hydroxide particles were readily converted to the nanosize Eu2O3 particles with an average size of 30 nm and a high BET surface area of 36.5 m2/g.

Luminescent Properties and Energy Transfer Mechanism of Gd^(3+) and Eu^(2+) Co-doped Phosphate Glasses

The phosphate glasses doped with Eu2＋, Gd3＋, respectively, and co-doped with Gd3＋ and Eu2＋ were prepared by high-temperature melting method. The transmission spectra, the excitation spectra, the emission spectra and the fluorescent decay time were investigated. The energy transfer process between Gd3＋ and Eu2＋ was studied. From the excitation spectra and the emission spectra of the phosphate glasses doped with Eu2＋, we observed that the emission intensity of Eu2＋ shows higher for 0.02 mol% Eu2＋-doped phosphate glass. According to the excitation spectra and the emission spectra and the fluorescence decay curves, when the concentration of Eu2＋ was 0.02 mol%, the optimal con- centration of Gd3＋ was 0.3 tool%. Based on Dexter theory, it is shown that the energy transfer between Gd3＋ and Eu2＋ was nonradiation energy transfer by analyzing the energy-level diagram. The fluorescence decay curves of Gd3＋ were expressed by the Inokuti-Hirayama＇s model and were used to analyze energy transfer mechanism between Gd3＋ and Eu2＋. And the energy transfer efficiency was also calculated.