The Preparation And Characteristic Of Rare Earth Sulfide And Oxysulfide Via The Thermolysis Method

In recent years, more and more attention has been paid to the rare earth elements sulfides due to its potential application in transfer material, fluorescence, laser, optical magnetic instrument etc. Traditional methods of its synthesis requires high purity of lanthanide ions, it also requires high purity of sulfur, or other source of sulfur such as hydrogen sulfide, carbon disulfide, which will cause serious environment pollutions. In the meantime, the method of preparing precursor via pyrolysis needs to react in high-boiling point organic solvents, but due to the presence of residual carbon which are formed by pyrolysis of organic, the products are impurely pure and show black color.Therefore, according to the defects and shortcomings of these methods above, simple solid phase direct thermal solution method has been chosen as the preparation method, and rare-earth sulfide and sulfur oxides have been synthesized in the atmosphere of sulfur vapor as decarbonizer. The major works in this paper are shown as follows:1. Gd2O2S:Yb,Ho have been prepared by the pyrolysis of Gd[S2CN(C4H8)]3-phen by introducing of oxygen (air) in the reaction system. The products are characterized by Fourier transform infrared spectroscopy (FTIR), photoluminescence spectroscopy (PL), etc. And the samples are proved to be excellent upconversion fluorescent materials with good color purity.2. Gd2S3 have been synthesized through the pyrolysis of precursor Gd[S2CN(C4Hg)]3-phen in a flow of argon and sulfur vapor. By the measurment of X-ray diffraction (XRD), scanning electron microscopy (SEM) and so on, we conformed that the products have uniform particle size and high purity. The introduction of sulfur atmosphere can effectively remove the carbon impurities in the product. The product shows black color under low temperature during the preparation, as the temperature rising, they become yellow gradually.3. Add copper with the same molar quantity as precursor Gd(Phen)(Ddtc)3 into the system, grind them thoroughly and then we get the product NaGdS2 after pyrogenation. The morphology of products are proved to be spherical,with high purity by the same testing methods as above. This is also a new method of preparing ternary rare earth sulfides (NaReS2).