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Study On The Phase Equilibrium System Of CsCl/CdCl2 And RECl3 Reacting In The Solution And Physical And Chemical Character Of The Compounds

Posted on:2002-12-25Degree:MasterType:Thesis
Country:ChinaCandidate:J X DuanFull Text:PDF
GTID:2121360032455520Subject:Inorganic Chemistry
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In this paper , phase chemistry relation that CsCl and RECl3(RE=Ce,Eu,Yb,Y) react in hydrochloric acid(HCl%=11,25℃) have been determined and the corresponding equilibrium diagrams were constructed. For the sake of widening the research field at the same time, on the basis of the research of rare alkali metal system, transition metal chlocide was choose to be the study object. Ternary systems CdCl2-RECl3-H2O (RE=La,Pr,Nd,Sm,Eu,Gd,30℃) have been investigated and the corresponding equilibrium diagrams were constructed. 6 types of 8 new compounds were found and obtained from the quaternary system, including 3CsCl·CeCl3·3H2O, CsCl·CeCl3·4H2O, 5CsCl·EuCl3·8H2O, 5CsCl·3EuCl3·16H2O, 4CsCl·YCl3·10H2O, 3CsCl·2YCl3·14H2O, 4CsCl·YbCl3·4H2O, 2CsCl·YbCl3·8H2O. In Ternary systems, 6 new compounds were found and obtain, including 4CdCl2·LaCl3·12H2O, 4CdCl2·PrCl3·12H2O, 4CdCl2·NdCl3·12H2O, 4CdCl2·SmCl3·12H2O, 4CdCl2·EuCl3·14H2O, 4CdCl2·GdCl3·14H2O. All of the 14 new compounds were investigated by X-ray powder diffraction, TG-DTG, DSC, and solid UV and fluorescence spectrum.Comparing the former with the work in this paper,the following new discovery were showed:1. 3:2 type new compound was obtained from the system first time.2. 5:1 type new compound was obtained from the system first time.3. Upconversion fluorescence phenomenon of new compounds is observed in different degree first time. Among all of new compounds obtained from the system, Upconversion fluorescence of 3CsCl·CeCl3·3H2O, CsCl·CeCl3·4H2O and 4CdCl2·NdCl3·12H2O are stronger. The result above is meaningful and worth for the new compounds to richen rare earth chemistry and investigate new character further. The research results of quaternary systems CsCl-RECl3-HCl-H2O show that the phase chemistry behaviors are same for system CsCl-RECl3-HCl-H2O (RE=La, Ce, Pr), and are same too for system CsCl-RECl3-HCl-H2O (RE=Gd, Yb). "Bicomponent effect" is obvious for the type of compound from La to Gd. But the diversity is evident about the phase chemistry behaviors for system CsCl-RECl3-HCl-H2O (RE=Pr, Nd, Sm.Eu.Gd). In particular, the character is more obvious in the system CsCl-RECl3-HCl-H2O (RE= Sm.Eu.Y). The research results of quaternary systems CdCl2-RECl3-H2O(RE=La, Pr, Nd, Sm, Eu, Gd,30℃) show that all of systems is same in the phase chemistry behaviors. Comparing the former with present research for ternary systems and quaternary systems, when cation is chloride ion, for the phase chemistry behaviors, the similarity of light rare earth is observed because of transition metal Cd2+ existing, the diversity of light rare earth is evident because of Cs+ existing. When cation is bromine ion, the similarity is express due to Cs+ existing. It is a new found and view about that phase chemistry behaviors of light rare earth chloride (RECl3/CdCl2, CsCl) have similarity because of Cd2+ existing and the diversity because of Cs+ existing in hydrochloric acid.
Keywords/Search Tags:quaternary systems, ternary systems, phase equilibrium, rare earth chloride, chloride cesium, chloride cadmium, similarity, diversity, upconversion, excitation and emission spectrum
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