The electro optical characteristics of SrS∶Ce and SrGa 2S 4∶Ce as two kinds of hopeful blue TFEL phosphors have been intensively investigated. The color purity of SrGa 2S 4∶Ce is better than that of SrS∶Ce. ...The electro optical characteristics of SrS∶Ce and SrGa 2S 4∶Ce as two kinds of hopeful blue TFEL phosphors have been intensively investigated. The color purity of SrGa 2S 4∶Ce is better than that of SrS∶Ce. In this paper, the influence of Ga 3+ on photoluminescence (PL) characteristics of Ce 3+ is first reported. Ga 2S 3 was doped into SrS, then sintered. The emission spectra shift obviously towards short wavelength range with increase of Ga 3+ concentration. At the same time, the relative intensity of the excitation peaks corresponding to the interband absorption of SrS reduces, and the excitation efficiency corresponding to the transition from the ground state to the excited state of Ce 3+ ion increases. The ligand field around Ce 3+ is changed by doped Ga 3+ . The ionicity of the substituted become stronger and Ce 3+ -Ce 3+ interaction become weaker. These are favorite to blue emission.展开更多
Ceria spheres with different sizes and sulfurized products with corresponding morphology were prepared by hydro-thermal and gas-solid reaction method at 600-800℃ under CS2 atmosphere for a short time, respectively. D...Ceria spheres with different sizes and sulfurized products with corresponding morphology were prepared by hydro-thermal and gas-solid reaction method at 600-800℃ under CS2 atmosphere for a short time, respectively. Dimensional effect in preparation ofγ-Ce2S3 was firstly investigated by means of techniques such as scanning electron microscopy （SEM）, X-ray dif-fraction （XRD）, thermal gravimetric analysis （TGA） and spectrophotometer. The results showed that when ceria nanoparticles with small size were used as precursors, theγ-Ce2S3 could be prepared at the lower temperature and the badly sintered products were obtained; when ceria nanoparticles with large size were employed as precursors, pureγ-Ce2S3 was difficultly obtained even if the temperature was up to 800℃ and the products tended to keep their original size. The heat-resistance property of theγ-Ce2S3 with large size was better than the smaller one, and the pureγ-Ce2S3 prepared from precursor with small size had a good pigmen-tary performance.展开更多
In this paper,a Sr^2+and Dy^3+co-doped γ-Ce2S3 red pigment was synthesized via a combination of coprecipitation and sulfurization processes.Mixed oxide was prepared by presintering the coprecipitates,(Ce,Sr,Dy)CO3,fo...In this paper,a Sr^2+and Dy^3+co-doped γ-Ce2S3 red pigment was synthesized via a combination of coprecipitation and sulfurization processes.Mixed oxide was prepared by presintering the coprecipitates,(Ce,Sr,Dy)CO3,followed by high-temperature sulfurization under a CS2 atmosphere.The effects of the sulfurization temperature,time,and doped proportion on the phase composition,color performance and temperature stability of γ-Ce2S3 were systematically studied.The results show that a stable γ-Ce2S3 red pigment can be obtained through Sr^2+and Dy^3+co-doping at 730℃ for 200 min.The diffraction peaks of all the samples shift to higher 2θ values with increasing doping proportion,indicating that part of the Dy^3+species enter the lattice and form a solid solution.The band gap of the samples remains practically constant at 2.01-2.04 eV,which causes their red color.The best red-color quality(L*=37.13,a*=34.77,b*=29.44) is achieved when the pigment has a Dy^3+/Ce^3+molar ratio of 0.15,and the material maintains its excellent red color(L*=31.49 a*=30.94 b*=25.33) after being heated at 410℃ for 30 min.展开更多
SiO2 coated Ce2S3 red pigment was prepared in ethanol/H2O system via sol-gel method and TEOS were used as silica sources. X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive spectroscopy...SiO2 coated Ce2S3 red pigment was prepared in ethanol/H2O system via sol-gel method and TEOS were used as silica sources. X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDX）, UV-visible spectro-photometer and automatic colorimeter were used to investigate the properties of the samples. The results showed that the compact SiO2 film formed on the surface of Ce2S3 pigment at a cerium silicon molar ratio of 2. The thermal stability temperature of Ce2S3 pigment was improved to 450 oC after SiO2 coating. In addition, the color of Ce2S3 pigment was not affected significantly through coating colorless and transparent SiO2 and it could be used as safe red pigment in higher temperature fields.展开更多
In this study,K+-doped γ-Ce2 S3 was successfully prepared via a gas-solid reaction method using CeO2,K2 CO3,and CS2 as raw materials.The effects of the suitable sulfide system and different molar ratios of K to Ce(nK...In this study,K+-doped γ-Ce2 S3 was successfully prepared via a gas-solid reaction method using CeO2,K2 CO3,and CS2 as raw materials.The effects of the suitable sulfide system and different molar ratios of K to Ce(nK/Ce=0-0.30) on the phase composition,crystal structure,chromaticity and thermal stability ofγ-Ce2 S3 were systematically investigated.Pure γ-Ce2 S3 was obtained by calcining the doped samples at840℃ for 150 min.After calcination at the same temperature the undoped K+samples exhibit a pure α-phase.Samples with a K/Ce molar ratio(nK/Ce) of 0.10-0.25 comprise only the γ-phase;and when nK/Ce exceeds 0.25,a new heterogeneous phase,KCeS2,emerges.For values of nK/Ce in the range of0-0.25,the γ-Ce2 S3 lattice parameters gradually increases with increasing K+ content.When nK/Ceexceedes 0.25,the lattice parameters remains unchanged.As nK/Ce increased,the synthesized color gradually changes from red to orange—red and finally,to yellow.The redness value a* reaches the maximum(L*=33.86,a*=36.68,b*=38.15) when nK/Ce=0.10,The nK/Ce=0.10 composition continues to exhibit the y-phase after heat treatment at 420℃ for 10 min in air.The K+doping fills the internal vacancies of γ-Ce2 S3 and formed a solid solution,which is beneficial for the stability of its lattice,thus improving the thermal stability of γ-Ce2 S3(from 350 to 420℃).展开更多
In order to investigate the suitability of ternary rare earth sulfide LanCe2 xS3 in plastic application as a red pigment, we prepared LaxCe2 xS3 via the sulfurization of the oxide powders using CS2 gas. In the sulfuri...In order to investigate the suitability of ternary rare earth sulfide LanCe2 xS3 in plastic application as a red pigment, we prepared LaxCe2 xS3 via the sulfurization of the oxide powders using CS2 gas. In the sulfurization of LaxCe2_xS3, β-phase and y-phase ter- nary rare earth sulfide LaxCe2_xS3 were synthesized at the sulfufization temperature of 1000 and 1250 ℃ for 3 h, respectively. The UV-vis absorption spectra of synthesized LaxCe2_xS3 showed that the absorption wavelengths of 13-phase and y-phase LaxCe2_xS3 samies were in the region of 617-70 nm and 607-53 nm, respectively. They were in red absorption region. Furthermore, the scanning electron microscopy （SEM） results of the synthesized LaxCe2-S3 samples were investigated. The typical SEM microgmphs indicated that the particle sizes of synthesized LaxCe2 xS3 were in the range of 0.5-5 μm.展开更多
文摘The electro optical characteristics of SrS∶Ce and SrGa 2S 4∶Ce as two kinds of hopeful blue TFEL phosphors have been intensively investigated. The color purity of SrGa 2S 4∶Ce is better than that of SrS∶Ce. In this paper, the influence of Ga 3+ on photoluminescence (PL) characteristics of Ce 3+ is first reported. Ga 2S 3 was doped into SrS, then sintered. The emission spectra shift obviously towards short wavelength range with increase of Ga 3+ concentration. At the same time, the relative intensity of the excitation peaks corresponding to the interband absorption of SrS reduces, and the excitation efficiency corresponding to the transition from the ground state to the excited state of Ce 3+ ion increases. The ligand field around Ce 3+ is changed by doped Ga 3+ . The ionicity of the substituted become stronger and Ce 3+ -Ce 3+ interaction become weaker. These are favorite to blue emission.
基金Project supported by the National Natural Science Foundation of China(20961006)Inner Mongolia Natural Science Foundation(20080404MS0201)Inner Mongolia Technology Innovation and Guidance Funds
文摘Ceria spheres with different sizes and sulfurized products with corresponding morphology were prepared by hydro-thermal and gas-solid reaction method at 600-800℃ under CS2 atmosphere for a short time, respectively. Dimensional effect in preparation ofγ-Ce2S3 was firstly investigated by means of techniques such as scanning electron microscopy （SEM）, X-ray dif-fraction （XRD）, thermal gravimetric analysis （TGA） and spectrophotometer. The results showed that when ceria nanoparticles with small size were used as precursors, theγ-Ce2S3 could be prepared at the lower temperature and the badly sintered products were obtained; when ceria nanoparticles with large size were employed as precursors, pureγ-Ce2S3 was difficultly obtained even if the temperature was up to 800℃ and the products tended to keep their original size. The heat-resistance property of theγ-Ce2S3 with large size was better than the smaller one, and the pureγ-Ce2S3 prepared from precursor with small size had a good pigmen-tary performance.
基金supported by the National Natural Science Foundation of China(51462010)the Natural Science Foundation of Jiangxi Province(20161BAB206132,20171ACB20022)the Science and technology program Foundation of Jingdezhen(2017GYZD019-012).
文摘In this paper,a Sr^2+and Dy^3+co-doped γ-Ce2S3 red pigment was synthesized via a combination of coprecipitation and sulfurization processes.Mixed oxide was prepared by presintering the coprecipitates,(Ce,Sr,Dy)CO3,followed by high-temperature sulfurization under a CS2 atmosphere.The effects of the sulfurization temperature,time,and doped proportion on the phase composition,color performance and temperature stability of γ-Ce2S3 were systematically studied.The results show that a stable γ-Ce2S3 red pigment can be obtained through Sr^2+and Dy^3+co-doping at 730℃ for 200 min.The diffraction peaks of all the samples shift to higher 2θ values with increasing doping proportion,indicating that part of the Dy^3+species enter the lattice and form a solid solution.The band gap of the samples remains practically constant at 2.01-2.04 eV,which causes their red color.The best red-color quality(L*=37.13,a*=34.77,b*=29.44) is achieved when the pigment has a Dy^3+/Ce^3+molar ratio of 0.15,and the material maintains its excellent red color(L*=31.49 a*=30.94 b*=25.33) after being heated at 410℃ for 30 min.
基金Project supported by National Science and Technology Support Program(2011BAE30B03)Special Fund from Shaanxi Provincial Department of Education(12JK0467the Graduate Innovation Fund of Shaanxi Universityof Science and Technology for the financial support
文摘SiO2 coated Ce2S3 red pigment was prepared in ethanol/H2O system via sol-gel method and TEOS were used as silica sources. X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDX）, UV-visible spectro-photometer and automatic colorimeter were used to investigate the properties of the samples. The results showed that the compact SiO2 film formed on the surface of Ce2S3 pigment at a cerium silicon molar ratio of 2. The thermal stability temperature of Ce2S3 pigment was improved to 450 oC after SiO2 coating. In addition, the color of Ce2S3 pigment was not affected significantly through coating colorless and transparent SiO2 and it could be used as safe red pigment in higher temperature fields.
基金Project supported by National Natural Science Foundation of China (51462010)Natural Science Foundation of Jiangxi Province(20161BAB206132,20171ACB20022)The Innovation fund of Jingdezhen Ceramic Institute (JYC-201803)。
文摘In this study,K+-doped γ-Ce2 S3 was successfully prepared via a gas-solid reaction method using CeO2,K2 CO3,and CS2 as raw materials.The effects of the suitable sulfide system and different molar ratios of K to Ce(nK/Ce=0-0.30) on the phase composition,crystal structure,chromaticity and thermal stability ofγ-Ce2 S3 were systematically investigated.Pure γ-Ce2 S3 was obtained by calcining the doped samples at840℃ for 150 min.After calcination at the same temperature the undoped K+samples exhibit a pure α-phase.Samples with a K/Ce molar ratio(nK/Ce) of 0.10-0.25 comprise only the γ-phase;and when nK/Ce exceeds 0.25,a new heterogeneous phase,KCeS2,emerges.For values of nK/Ce in the range of0-0.25,the γ-Ce2 S3 lattice parameters gradually increases with increasing K+ content.When nK/Ceexceedes 0.25,the lattice parameters remains unchanged.As nK/Ce increased,the synthesized color gradually changes from red to orange—red and finally,to yellow.The redness value a* reaches the maximum(L*=33.86,a*=36.68,b*=38.15) when nK/Ce=0.10,The nK/Ce=0.10 composition continues to exhibit the y-phase after heat treatment at 420℃ for 10 min in air.The K+doping fills the internal vacancies of γ-Ce2 S3 and formed a solid solution,which is beneficial for the stability of its lattice,thus improving the thermal stability of γ-Ce2 S3(from 350 to 420℃).
基金Project supported by National Natural Science Foundation of China (20501023)Natural Science Foundation of Henan Province (2010A430010)Scientific and Technical Foundation of China National Coal Association (MTKJ2010-357)
文摘In order to investigate the suitability of ternary rare earth sulfide LanCe2 xS3 in plastic application as a red pigment, we prepared LaxCe2 xS3 via the sulfurization of the oxide powders using CS2 gas. In the sulfurization of LaxCe2_xS3, β-phase and y-phase ter- nary rare earth sulfide LaxCe2_xS3 were synthesized at the sulfufization temperature of 1000 and 1250 ℃ for 3 h, respectively. The UV-vis absorption spectra of synthesized LaxCe2_xS3 showed that the absorption wavelengths of 13-phase and y-phase LaxCe2_xS3 samies were in the region of 617-70 nm and 607-53 nm, respectively. They were in red absorption region. Furthermore, the scanning electron microscopy （SEM） results of the synthesized LaxCe2-S3 samples were investigated. The typical SEM microgmphs indicated that the particle sizes of synthesized LaxCe2 xS3 were in the range of 0.5-5 μm.
