Eu doped γ-La2S3 were synthesized by the sulfurization of their oxide powders using CS2 gas at 700 ℃. During the sulfurizing reaction process, the cubic Eu3S4 crystals of prior formation acted as the nuclei sites of...Eu doped γ-La2S3 were synthesized by the sulfurization of their oxide powders using CS2 gas at 700 ℃. During the sulfurizing reaction process, the cubic Eu3S4 crystals of prior formation acted as the nuclei sites of the γ-La2S3 phase to facilitate the nucleation process. The γ-La2S3 transformation occurred at significantly lower temperature by the combined contributions of low transformation enthalpy and induced multiple nuclei. On the other hand, the doped Eu ions could be inserted into the empty tetrahedral S4 cavities to stabilize the γ-La2S3 phase at temperature excess of 1100 ℃.展开更多
Pure γ-Gd2S3 was synthesized by the thermolysis of a single Gd[S2CN（C4H8）]3 phen complex precursor in a flow of argon carrier gas containing sulfur vapor. The complex precursor was decomposed into amorphous Gd2S3 a...Pure γ-Gd2S3 was synthesized by the thermolysis of a single Gd[S2CN（C4H8）]3 phen complex precursor in a flow of argon carrier gas containing sulfur vapor. The complex precursor was decomposed into amorphous Gd2S3 and carbon at about 350 ℃. Crystalline y-Gd2S3 could be achieved at temperature exceeding 600 ℃, and the obtained γ-Gd2S3 presented a very high degree of crystallinity at 800 ℃. Carbon prevented the formation of Gd2O2S impurity in the preparation of y-Gd2S3. However, the carbon blackened the product. At temperature ≥ 1000 ℃, the residual carbon impurity could be efficiently removed by introducing sulfur into the system for the volatile CS2 could be formed in situ via the reaction of sulfur with the deposited carbon. In the meantime, S also promoted the crystallization of γ-Gd2S3 remarkablely.展开更多
基金supported by New Century Educational Talents Plan of Chinese Education Ministry, China (NCET-10-0171)the National Natural Sci-ence Foundation of China (60979003)the Fundamental Research Funds for the Central Universities (2009QN123)
文摘Eu doped γ-La2S3 were synthesized by the sulfurization of their oxide powders using CS2 gas at 700 ℃. During the sulfurizing reaction process, the cubic Eu3S4 crystals of prior formation acted as the nuclei sites of the γ-La2S3 phase to facilitate the nucleation process. The γ-La2S3 transformation occurred at significantly lower temperature by the combined contributions of low transformation enthalpy and induced multiple nuclei. On the other hand, the doped Eu ions could be inserted into the empty tetrahedral S4 cavities to stabilize the γ-La2S3 phase at temperature excess of 1100 ℃.
基金Project supported by National Natural Science Foundation of China(60979003)New Century Educational Talents Plan of Chinese EducationMinistry,China(NCET-10-0171)+1 种基金Fundamental Research Funds for the Central Universities(2011QN153,2012QN065,2012QN068,2012TD018)Scientific Research Fund of Zhejiang Provincial Education Department(Y201121038)
文摘Pure γ-Gd2S3 was synthesized by the thermolysis of a single Gd[S2CN（C4H8）]3 phen complex precursor in a flow of argon carrier gas containing sulfur vapor. The complex precursor was decomposed into amorphous Gd2S3 and carbon at about 350 ℃. Crystalline y-Gd2S3 could be achieved at temperature exceeding 600 ℃, and the obtained γ-Gd2S3 presented a very high degree of crystallinity at 800 ℃. Carbon prevented the formation of Gd2O2S impurity in the preparation of y-Gd2S3. However, the carbon blackened the product. At temperature ≥ 1000 ℃, the residual carbon impurity could be efficiently removed by introducing sulfur into the system for the volatile CS2 could be formed in situ via the reaction of sulfur with the deposited carbon. In the meantime, S also promoted the crystallization of γ-Gd2S3 remarkablely.
