The development of rare earths (RE) applications to semiconductor materials and devices is reviewed. The recent advances in RE doped silicon light emitting diodes (LED) and display materials are described. The various...The development of rare earths (RE) applications to semiconductor materials and devices is reviewed. The recent advances in RE doped silicon light emitting diodes (LED) and display materials are described. The various technologies of incorporating RE into semiconductor materials and devices are presented. The RE high dielectric materials, RE silicides and the phase transition of RE materials are also discussed. Finally, the paper describes the prospects of the RE application to semiconductor industry.展开更多
Herein an estimation is given to the efficiency of nuclear explosive devices in a space-rocket complex to withdraw Hazardous Space Objects （HS0）-asteroids and cometary nuclei from the trajectories leading to their d...Herein an estimation is given to the efficiency of nuclear explosive devices in a space-rocket complex to withdraw Hazardous Space Objects （HS0）-asteroids and cometary nuclei from the trajectories leading to their dangerous entry to the atmosphere and falling to the Earth. A conceptual choice of parameters and schemes of application of nuclear explosive devices in impact modules of space-rocket complexes to ensure asteroidal-cometary safety was made.展开更多
Photoluminescence （PL） characteristics of Tb-doped silicon rich oxide （SRO） films prepared by DC-sputtering and post-annealing processes were studied. The silicon richness of the SRO film could be controlled by va...Photoluminescence （PL） characteristics of Tb-doped silicon rich oxide （SRO） films prepared by DC-sputtering and post-annealing processes were studied. The silicon richness of the SRO film could be controlled by varying the sputtering power and oxygen concentration in the sputtering chamber. PL emission from the as-deposited sample was found to be composed of Th^3 ＋ intra 4f transition-related emission and the silicon nano particle-related broad bandwidth emission. Thermal annealing could significantly improve the material properties as well as the PL signals. PL properties depended strongly upon the annealing scheme and silicon richness. Annealing at high temperatures （900- 1050℃） enhanced Tbrelated emission and suppressed the silicon nano particle-related emission. For samples with different silicon richness, annealing at 950 ℃ was found to produce higher PL signals than at other temperatures. It was attributed more to lifetime quenching than to concentration quenching. Electroluminescent （EL） devices with a capacitor structure were fabricated, the optimized process condition for the EL device was found to be different from that of PL emission. Among the annealing schemes that were used, wet oxidation was found to improve device performance the most, whereas, dry oxidation was found to improve material property the most. Wet oxidation allowed the breakdown electrical field to increase significantly and to reach above 10 mV·cm^-1. The EL spectra showed a typical Th^3＋ emission, agreeing well with the PL spectra. The I-V measurements indicated that for 100 nm thick film, the Fowler-Nordheim tunneling started at an electrical field of around 6 mV·cm^-1 and the light emission became detectable at a current density of around 10-4 A·cm^-2 and higher. Strong electroluminescence light emission was detected when the electrical field was close to 10 mV·cm^-1.展开更多
Polyimide (Kapton, Dupont Corp.) based magnetostrictive thin film structures were designed and fabricated for micro device applications. In particular the growth of films on flexible substrates was studied to allow a ...Polyimide (Kapton, Dupont Corp.) based magnetostrictive thin film structures were designed and fabricated for micro device applications. In particular the growth of films on flexible substrates was studied to allow a simple integration of the system in miniaturized magnetostrictive devices. The films were fabricated on different substrates to compare their different magnetic and structural properties. It showed much more magnetostriction and higher impact resistance results compared with traditional Si based film type actuators. In the fabrication process, amorphous TbDyFe films with thicknesses of 500 nm, 1 μm, 1.5 μm respectively, were deposited on the designed substrate by DC magnetron sputtering. During sputtering process the substrate holder was maintained at room temperature. After the sputter process, X-ray diffraction studies were also carried out to determine the film structure and thickness of the sputtered film. At last, magnetization from VSM (Vibrating Sample Magnetometer) and magnetostriction from optical cantilever method of each structure were measured to estimate the magneto-mechanical characteristics under the external magnetic field lower than 0.7 T for micro-system applications.展开更多
A gadolinium ternary complex, tris(1 phenyl 3 methyl 4 isobutyryl 5 pyrazolone) (2, 2′ dipyridyl) gadolinium Gd(PMIP) 3(Bipy) was synthesized and used as a light emitting material in the organic electrolumin...A gadolinium ternary complex, tris(1 phenyl 3 methyl 4 isobutyryl 5 pyrazolone) (2, 2′ dipyridyl) gadolinium Gd(PMIP) 3(Bipy) was synthesized and used as a light emitting material in the organic electroluminescent devices. The devices exhibited the green electroluminescent (EL) emission peaking at 513 nm, originating from the Gd(PMIP) 3(Bipy). By improving the configuration, the device with a structure of ITO/poly(N vinylcarbazole) (PVK) (40 nm)/Gd(PMIP) 3(Bipy) (40 nm)/tris (8 hydroxyquinoline) aluminum (ALQ) (40 nm)/Mg∶Ag(200 nm)/Ag(100 nm) showed higher performance and a maximum luminance of 340 cd·m -2 at 18 V.展开更多
As a material with good biocompatibility,hydroxyapatite(HAP)can have optical properties after doping with various rare earth ions.As a biocompatible fluorescent material,doped HAP could have broad applications in biol...As a material with good biocompatibility,hydroxyapatite(HAP)can have optical properties after doping with various rare earth ions.As a biocompatible fluorescent material,doped HAP could have broad applications in biological probes,drug delivery,optoelectronic materials,fluorescence anti-counterfeiting,and other aspects.In this paper,we put forward the preparation of HAP doped with terbium(Ⅲ)ions(Tb^(3+))by hydrothermal co-precipitation.By controlling the Tb^(3+)doping content in reaction and the reaction time,the changes in HAP's structure,morphology,and luminescence properties under different conditions were studied.When the doping amount of Tb^(3+)reached an optimal value,the dipole-quadrupole would occur and the concentration would be quenched.The control experiment showed that the optimal Tb3+content was 7.5×10^(-5)mol,which showed the best fluorescence performance.HAP,a non-luminous material,was rarely used in the field of fluorescent anti-counterfeiting and photoelectric devices.We proposed to prepare a luminescent aramid/polyphenylene sulfide(ACFs/PPS)fiber paper and a new light-emitting diode(LED)using the Tb-doped HAP phosphor.The composite sample exhibited an excellent stability and fluorescence performance,which also demonstrated a possibility of HAP applications in anticounterfeiting and photoelectric.The introduction of Tb3+dopant HAP was done to give HAP optical properties and broaden the application range of HAP.展开更多
Ca1-xRxCu3Ti4O12(R=La,Y,Gd;x=0,0.1,0.2,0.3) electronic ceramics were fabricated by conventional solid-state reaction method.The microstructure and dielectric properties as well as impedance behavior were carefully inv...Ca1-xRxCu3Ti4O12(R=La,Y,Gd;x=0,0.1,0.2,0.3) electronic ceramics were fabricated by conventional solid-state reaction method.The microstructure and dielectric properties as well as impedance behavior were carefully investigated.XRD results showed that the secondary phases with the general formula R2Ti2O7 existed at grain boundaries of rare earth doped ceramics,which inhibited abnormal grain growth.The dielectric constant decreased from 4×105 in pure CaCu3Ti4O12(CCTO) ceramics to 2×103 with rare earth doping....展开更多
文摘The development of rare earths (RE) applications to semiconductor materials and devices is reviewed. The recent advances in RE doped silicon light emitting diodes (LED) and display materials are described. The various technologies of incorporating RE into semiconductor materials and devices are presented. The RE high dielectric materials, RE silicides and the phase transition of RE materials are also discussed. Finally, the paper describes the prospects of the RE application to semiconductor industry.
文摘Herein an estimation is given to the efficiency of nuclear explosive devices in a space-rocket complex to withdraw Hazardous Space Objects （HS0）-asteroids and cometary nuclei from the trajectories leading to their dangerous entry to the atmosphere and falling to the Earth. A conceptual choice of parameters and schemes of application of nuclear explosive devices in impact modules of space-rocket complexes to ensure asteroidal-cometary safety was made.
文摘Photoluminescence （PL） characteristics of Tb-doped silicon rich oxide （SRO） films prepared by DC-sputtering and post-annealing processes were studied. The silicon richness of the SRO film could be controlled by varying the sputtering power and oxygen concentration in the sputtering chamber. PL emission from the as-deposited sample was found to be composed of Th^3 ＋ intra 4f transition-related emission and the silicon nano particle-related broad bandwidth emission. Thermal annealing could significantly improve the material properties as well as the PL signals. PL properties depended strongly upon the annealing scheme and silicon richness. Annealing at high temperatures （900- 1050℃） enhanced Tbrelated emission and suppressed the silicon nano particle-related emission. For samples with different silicon richness, annealing at 950 ℃ was found to produce higher PL signals than at other temperatures. It was attributed more to lifetime quenching than to concentration quenching. Electroluminescent （EL） devices with a capacitor structure were fabricated, the optimized process condition for the EL device was found to be different from that of PL emission. Among the annealing schemes that were used, wet oxidation was found to improve device performance the most, whereas, dry oxidation was found to improve material property the most. Wet oxidation allowed the breakdown electrical field to increase significantly and to reach above 10 mV·cm^-1. The EL spectra showed a typical Th^3＋ emission, agreeing well with the PL spectra. The I-V measurements indicated that for 100 nm thick film, the Fowler-Nordheim tunneling started at an electrical field of around 6 mV·cm^-1 and the light emission became detectable at a current density of around 10-4 A·cm^-2 and higher. Strong electroluminescence light emission was detected when the electrical field was close to 10 mV·cm^-1.
文摘Polyimide (Kapton, Dupont Corp.) based magnetostrictive thin film structures were designed and fabricated for micro device applications. In particular the growth of films on flexible substrates was studied to allow a simple integration of the system in miniaturized magnetostrictive devices. The films were fabricated on different substrates to compare their different magnetic and structural properties. It showed much more magnetostriction and higher impact resistance results compared with traditional Si based film type actuators. In the fabrication process, amorphous TbDyFe films with thicknesses of 500 nm, 1 μm, 1.5 μm respectively, were deposited on the designed substrate by DC magnetron sputtering. During sputtering process the substrate holder was maintained at room temperature. After the sputter process, X-ray diffraction studies were also carried out to determine the film structure and thickness of the sputtered film. At last, magnetization from VSM (Vibrating Sample Magnetometer) and magnetostriction from optical cantilever method of each structure were measured to estimate the magneto-mechanical characteristics under the external magnetic field lower than 0.7 T for micro-system applications.
文摘A gadolinium ternary complex, tris(1 phenyl 3 methyl 4 isobutyryl 5 pyrazolone) (2, 2′ dipyridyl) gadolinium Gd(PMIP) 3(Bipy) was synthesized and used as a light emitting material in the organic electroluminescent devices. The devices exhibited the green electroluminescent (EL) emission peaking at 513 nm, originating from the Gd(PMIP) 3(Bipy). By improving the configuration, the device with a structure of ITO/poly(N vinylcarbazole) (PVK) (40 nm)/Gd(PMIP) 3(Bipy) (40 nm)/tris (8 hydroxyquinoline) aluminum (ALQ) (40 nm)/Mg∶Ag(200 nm)/Ag(100 nm) showed higher performance and a maximum luminance of 340 cd·m -2 at 18 V.
基金financially supported by the National Natural Science Foundation of China(Nos.52274273 and 51872269)the Key Laboratory of Testing and Tracing of Rare Earth Products for State Market Regulation(Jiangxi University of Science and Technology)(No.TTREP2022YB04)+4 种基金the Science and Technology Research Project of Hubei Provincial Department of Education(No.B2021091)Key Laboratory for New Textile Materials and Applications of Hubei Province(Wuhan Textile University)(No.FZXCL202107)the Open Project Program of High-Tech Organic Fibers Key Laboratory of Sichuan ProvinceChina and National Project Cultivation Plan of Wuhan Textile Universityaided by the graduate innovation fund project of Wuhan Textile University。
文摘As a material with good biocompatibility,hydroxyapatite(HAP)can have optical properties after doping with various rare earth ions.As a biocompatible fluorescent material,doped HAP could have broad applications in biological probes,drug delivery,optoelectronic materials,fluorescence anti-counterfeiting,and other aspects.In this paper,we put forward the preparation of HAP doped with terbium(Ⅲ)ions(Tb^(3+))by hydrothermal co-precipitation.By controlling the Tb^(3+)doping content in reaction and the reaction time,the changes in HAP's structure,morphology,and luminescence properties under different conditions were studied.When the doping amount of Tb^(3+)reached an optimal value,the dipole-quadrupole would occur and the concentration would be quenched.The control experiment showed that the optimal Tb3+content was 7.5×10^(-5)mol,which showed the best fluorescence performance.HAP,a non-luminous material,was rarely used in the field of fluorescent anti-counterfeiting and photoelectric devices.We proposed to prepare a luminescent aramid/polyphenylene sulfide(ACFs/PPS)fiber paper and a new light-emitting diode(LED)using the Tb-doped HAP phosphor.The composite sample exhibited an excellent stability and fluorescence performance,which also demonstrated a possibility of HAP applications in anticounterfeiting and photoelectric.The introduction of Tb3+dopant HAP was done to give HAP optical properties and broaden the application range of HAP.
基金supported by the National Basic Research Program of China (973) (2007CB31407)Foundation for Innovative Research Groups of the NSFC (60721001)+1 种基金the Young Fund of Sichuan Province (08ZQ026-013)the National Natural Science Foundation of China (50972023, 50872078)
文摘Ca1-xRxCu3Ti4O12(R=La,Y,Gd;x=0,0.1,0.2,0.3) electronic ceramics were fabricated by conventional solid-state reaction method.The microstructure and dielectric properties as well as impedance behavior were carefully investigated.XRD results showed that the secondary phases with the general formula R2Ti2O7 existed at grain boundaries of rare earth doped ceramics,which inhibited abnormal grain growth.The dielectric constant decreased from 4×105 in pure CaCu3Ti4O12(CCTO) ceramics to 2×103 with rare earth doping....
