In this study,a single-doped phosphors yttrium aluminum garnet(Y_(3)Al_(5)O_(12),YAG):Ce^(3+),single-doped YAG:Sc^(3+),and double-doped phosphors YAG:Ce^(3+),Sc^(3+) were prepared by spark plasma sintering(SPS)(lower ...In this study,a single-doped phosphors yttrium aluminum garnet(Y_(3)Al_(5)O_(12),YAG):Ce^(3+),single-doped YAG:Sc^(3+),and double-doped phosphors YAG:Ce^(3+),Sc^(3+) were prepared by spark plasma sintering(SPS)(lower than 1 200℃).The characteristics of synthesized phosphors were determined using scanning electron microscopy(SEM),X-ray diffraction(XRD),and fluorescence spectroscopy.During SPS,the lattice structure of YAG was maintained by the added Ce^(3+) and Sc^(3+).The emission wavelength of YAG:Ce^(3+) prepared from SPS(425-700 nm) was wider compared to that of YAG:Ce^(3+) prepared from high-temperature solid-state reaction(HSSR)(500-700 nm).The incorporation of low-dose Sc^(3+) in YAG:Ce^(3+) moved the emission peak towards the short wavelength.展开更多
Layered alkali-containing 3d transition-metal oxides are of the utmost importance in the use of electrode materials for advanced energy storage applications such as Li-,Na-,or K-ion batteries.A significant challenge i...Layered alkali-containing 3d transition-metal oxides are of the utmost importance in the use of electrode materials for advanced energy storage applications such as Li-,Na-,or K-ion batteries.A significant challenge in the field of materials chemistry is understanding the dynamics of the chemical reactions between alkali-free precursors and alkali species during the synthesis of these compounds.In this study,in situ high-resolution synchrotron-based X-ray diffraction was applied to reveal the Li/Na/K-ion insertion-induced structural transformation mechanism during high-temperature solid-state reaction.The in situ diffraction results demonstrate that the chemical reaction pathway strongly depends on the alkali-free precursor type,which is a structural matrix enabling phase transi-tions.Quantitative phase analysis identifies for the first time the decomposition of lithium sources as the most critical factor for the formation of metastable intermediates or impurities during the entire process of Li-rich layered Li[Li_(0.2)Ni_(0.2)Mn_(0.6)]O_(2) formation.Since the alkali ions have different ionic radii,Na/K ions tend to be located on prismatic sites in the defective layered structure(Na_(2/3-x)[Ni_(0.25)Mn_(0.75)]O_(2) or K_(2/3-x)[Ni_(0.25)Mn_(0.75)]O_(2))during calcination,whereas the Li ions prefer to be localized on the tetrahedral and/or octahedral sites,forming O-type structures.展开更多
Two new rare-earth metal chalcogenides,namely RbLu5Te8 and CsMnGdTe3,have been successfully synthesized under high-temperature solid-state reaction conditions and structurally characterized by single-crystal X-ray dif...Two new rare-earth metal chalcogenides,namely RbLu5Te8 and CsMnGdTe3,have been successfully synthesized under high-temperature solid-state reaction conditions and structurally characterized by single-crystal X-ray diffraction analysis.RbLu5Te8 belongs to the monoclinic space group C2/m(no.12)with two formula units in a unit cell:a=22.075(5),b=4.2987(8),c=10.588(2)A,β=103.89(2)°,V=975.4(4)A3,whereas CsMnGdTe3 crystallizes in the orthorhombic space group Cmcm(no.63)with four formula units in a unit cell:a=4.4872(8),b=16.769(3),c=11.807(2)A and V=888.4(3)A3.In the structure of RbLu5Te8,face-,edgeand vertex-sharing[LuTe6]octahedra are interconnected to produce a three-dimensional(3D)framework with Rb^+lying in the tunnels.The crystal structure of CsMnGdTe3 consists of two-dimensional(2D)[MnGdTe3]^–layers of edge-and vertex-sharing[GdTe6]octahedra with Mn atoms filling the tetrahedral interstices,which stack along the b-axis.The Cs atoms are located between the[MnGdTe3]^–layers and surrounded by eight Te atoms to form a[CsTe8]bicapped trigonal prism.Moreover,theoretical studies have aided the understanding of their electronic structures.展开更多
The principle of miniature isolated solid-state encapsulation technology of high-temperature pressure sensor and the structure of packaging are discussed, including static electricity bonding, stainless steel diaphrag...The principle of miniature isolated solid-state encapsulation technology of high-temperature pressure sensor and the structure of packaging are discussed, including static electricity bonding, stainless steel diaphragm selection and rippled design, laser welding, silicon oil infilling, isolation and other techniques used in sensor packaging, which can affect the performance of the sensor. By adopting stainless steel diaphragm and high-temperature silicon oil as isolation materials, not only the encapsulation of the sensor is as small as 15 mm in diameter and under 1 mA drive, its full range output is 72 mV and zero stability is 0.48% F.S/mon, but also the reliability of the sensor is improved and its application is widely broadened.展开更多
基金Funded by the Primary Research and Development Plan of Jiangsu Province(No.BE2016175)。
文摘In this study,a single-doped phosphors yttrium aluminum garnet(Y_(3)Al_(5)O_(12),YAG):Ce^(3+),single-doped YAG:Sc^(3+),and double-doped phosphors YAG:Ce^(3+),Sc^(3+) were prepared by spark plasma sintering(SPS)(lower than 1 200℃).The characteristics of synthesized phosphors were determined using scanning electron microscopy(SEM),X-ray diffraction(XRD),and fluorescence spectroscopy.During SPS,the lattice structure of YAG was maintained by the added Ce^(3+) and Sc^(3+).The emission wavelength of YAG:Ce^(3+) prepared from SPS(425-700 nm) was wider compared to that of YAG:Ce^(3+) prepared from high-temperature solid-state reaction(HSSR)(500-700 nm).The incorporation of low-dose Sc^(3+) in YAG:Ce^(3+) moved the emission peak towards the short wavelength.
基金the National Natural Science Foundation of China(grant no.22108218)“Young Talent Support Plan”of Xi'an Jiaotong University(71211201010723)+6 种基金This work was financially supported by the China Postdoctoral Science Foundation(Grant No.2021M693813)Guangxi Science and Technology Base and Talents Special Project(Grant No.AD21159007)the Natural Science Foundation of Guangxi(Grant No.2020GXNSFBA297029)the Foundation of Key Laboratory of New Processing Technology for Nonferrous Metal&Materials,Ministry of Education/Guangxi Key Laboratory of Optical and Electronic Materials and Devices,Guilin University of Technology(Contract No.20AA-13)the Foundation of Guilin University of Tech-nology(GLUTQDJJ2020003)High Level Innovation Team and Outstanding Scholar Program of Guangxi Institutes.We acknowledge DESY(Hamburg,Germany),a member of the Helmholtz Association HGF,and Paul Scherrer Institut(Villigen PSI,Switzerland)for the provision of experimental facilitiescontributes to the research performed at CELEST(Center for Electro-chemical Energy Storage Ulm-Karlsruhe)and was supported by the German Research Foundation(DFG)under Project ID 390874152(POLiS Cluster of Excellence).
文摘Layered alkali-containing 3d transition-metal oxides are of the utmost importance in the use of electrode materials for advanced energy storage applications such as Li-,Na-,or K-ion batteries.A significant challenge in the field of materials chemistry is understanding the dynamics of the chemical reactions between alkali-free precursors and alkali species during the synthesis of these compounds.In this study,in situ high-resolution synchrotron-based X-ray diffraction was applied to reveal the Li/Na/K-ion insertion-induced structural transformation mechanism during high-temperature solid-state reaction.The in situ diffraction results demonstrate that the chemical reaction pathway strongly depends on the alkali-free precursor type,which is a structural matrix enabling phase transi-tions.Quantitative phase analysis identifies for the first time the decomposition of lithium sources as the most critical factor for the formation of metastable intermediates or impurities during the entire process of Li-rich layered Li[Li_(0.2)Ni_(0.2)Mn_(0.6)]O_(2) formation.Since the alkali ions have different ionic radii,Na/K ions tend to be located on prismatic sites in the defective layered structure(Na_(2/3-x)[Ni_(0.25)Mn_(0.75)]O_(2) or K_(2/3-x)[Ni_(0.25)Mn_(0.75)]O_(2))during calcination,whereas the Li ions prefer to be localized on the tetrahedral and/or octahedral sites,forming O-type structures.
基金the National Natural Science Foundation of China(21771179 and 21301175)the Natural Science Foundation of Fujian Province(2019J01133)+1 种基金the Foundation of State Key Laboratory of Structural Chemistry(20190033)Distinguished Young Scientific Research Talents Plan in Universities of Fujian Province(201847)。
文摘Two new rare-earth metal chalcogenides,namely RbLu5Te8 and CsMnGdTe3,have been successfully synthesized under high-temperature solid-state reaction conditions and structurally characterized by single-crystal X-ray diffraction analysis.RbLu5Te8 belongs to the monoclinic space group C2/m(no.12)with two formula units in a unit cell:a=22.075(5),b=4.2987(8),c=10.588(2)A,β=103.89(2)°,V=975.4(4)A3,whereas CsMnGdTe3 crystallizes in the orthorhombic space group Cmcm(no.63)with four formula units in a unit cell:a=4.4872(8),b=16.769(3),c=11.807(2)A and V=888.4(3)A3.In the structure of RbLu5Te8,face-,edgeand vertex-sharing[LuTe6]octahedra are interconnected to produce a three-dimensional(3D)framework with Rb^+lying in the tunnels.The crystal structure of CsMnGdTe3 consists of two-dimensional(2D)[MnGdTe3]^–layers of edge-and vertex-sharing[GdTe6]octahedra with Mn atoms filling the tetrahedral interstices,which stack along the b-axis.The Cs atoms are located between the[MnGdTe3]^–layers and surrounded by eight Te atoms to form a[CsTe8]bicapped trigonal prism.Moreover,theoretical studies have aided the understanding of their electronic structures.
文摘The principle of miniature isolated solid-state encapsulation technology of high-temperature pressure sensor and the structure of packaging are discussed, including static electricity bonding, stainless steel diaphragm selection and rippled design, laser welding, silicon oil infilling, isolation and other techniques used in sensor packaging, which can affect the performance of the sensor. By adopting stainless steel diaphragm and high-temperature silicon oil as isolation materials, not only the encapsulation of the sensor is as small as 15 mm in diameter and under 1 mA drive, its full range output is 72 mV and zero stability is 0.48% F.S/mon, but also the reliability of the sensor is improved and its application is widely broadened.
