The FFC Cambridge process is a direct electrodeoxidation process used to reduce metal oxides for metals or alloys in molten salts. Al-Sc compound oxides are used as a precursor which formed upon blending and sintering...The FFC Cambridge process is a direct electrodeoxidation process used to reduce metal oxides for metals or alloys in molten salts. Al-Sc compound oxides are used as a precursor which formed upon blending and sintering Al2O3, Sc2O3 and AI powders and are successfully reduced by using the FFC Cambridge process at 973 K with a constant cell voltage of -3.2 V. This method is applied to the preparation of fine Al3Sc particles, which can give another new view for aluminum industry.展开更多
Gd3Sc2Ga3O12 polycrystalline material for single crystal growth was prepared with Ga, Gd2O3 and Sc2O3 as starting materials and aqueous ammonia as the precipitator by co-precipitation method. The precursors sintered a...Gd3Sc2Ga3O12 polycrystalline material for single crystal growth was prepared with Ga, Gd2O3 and Sc2O3 as starting materials and aqueous ammonia as the precipitator by co-precipitation method. The precursors sintered at various temperatures were characterized by infrared spectra （IR）, X-ray diffractometry （XRD） and transmitted electron microscopy （TEM）. The results showed that pure GSGG phase could be obtained at 900 ℃. The sintered powders were well-dispersed and less-aggregated in the sintered temperature range of 900 - 1000 ℃. XRD and TEM show that the polycrystalline particle sizes of the polycrystalline powders were about 20 - 50 nm. Compared with the method that Ga2O3, Gd2O3 and Sc2O3 were mixed directly and sintered to get polycrystalline materials, the synthesized temperature was lower and sintered time was shorter. Thus co-precipitation was a good method to synthesize GSGG polycrystalline material.展开更多
Absorption, excitation and emission spectra as well as decay time measurements at 10, 77, and 300 K were perfumed for Gd3Sc2Ga3O12 garnet single-crystal doped with Cr^3＋ and Nd^3＋ ions. Strong reabsorption of Cr3＋ ...Absorption, excitation and emission spectra as well as decay time measurements at 10, 77, and 300 K were perfumed for Gd3Sc2Ga3O12 garnet single-crystal doped with Cr^3＋ and Nd^3＋ ions. Strong reabsorption of Cr3＋ emission by Nd3＋ absorption lines was ob- served. The assignments of f-f and d-d transitions were proposed. The broad emission band of chromium ions is an indication that weak/intermediate crystal field strength is present at the Cr3＋ site.展开更多
Single crystal of cobalt (Co)-doped Y3Sc2Ga3O12 (YSGG) with the dimensions up to Φ20×40 mm3 and undoped YSGG crystal with the dimensions up to Φ28×60 mm3 have been grown using the Czochralski technique. Th...Single crystal of cobalt (Co)-doped Y3Sc2Ga3O12 (YSGG) with the dimensions up to Φ20×40 mm3 and undoped YSGG crystal with the dimensions up to Φ28×60 mm3 have been grown using the Czochralski technique. The structure of the crystal was characterized by the X-ray powder diffraction (XRPD) method. The absorbance spectra of the crystal shows that it has strong absorption bands at 606 and 1540 nm. The results indicate that the crystal Y3Sc2Ga3O12 may be a kind of good Q-switch material.展开更多
The ab initio method has been performed to explore the elastic and optical properties of Al3Sc compound, based on a plane wave pseudopotential method. It can be seen that the calculated equilibrium lattice parameter a...The ab initio method has been performed to explore the elastic and optical properties of Al3Sc compound, based on a plane wave pseudopotential method. It can be seen that the calculated equilibrium lattice parameter and elastic constants are in reasonable agreement with the previous experimental data. The elastic constants satisfy the requirement for mechanical stability in the cubic structure of the Al3Sc compound. The optical property calculations show that a strong absorptive peak exists from O-15eV and a relative small absorptive peak exists around 30eV. The form is caused by the optical transitions between high s, p, and d bands, and the latter results from the optical transitions from high s, p, and d bands to the low 2p band.展开更多
Al-Sc alloys with high Sc contents are served as sputtering targets for making high-performance piezoelectric devices.The micro structure of these alloys would affect the sputtering process and the final quality of th...Al-Sc alloys with high Sc contents are served as sputtering targets for making high-performance piezoelectric devices.The micro structure of these alloys would affect the sputtering process and the final quality of the functional devices.In this study,the microstructure in as-c as ted Al-20%Sc(in atomic ratio)alloys is characterized and the feathery Al3Sc grains with twin relationships are reported for the first time.The crystallographic features of twined structures and growth directions are quantitatively analyzed by electron backscatter diffraction(EBSD)technique.展开更多
基金This work was supported by the National Key Basic Research Program of China （No.2013CB921800）, the National Natural Science Foundation of China （No.11374291, No.11311120047, No.11274299, No.11447197, and No.11204292）, the Fundamen- tal Research Funds for the Central Universities （No.WK20304200）, the Anhui Provincial Natural Science Foundation （No.1508085QA09）. The numerical calculations have been partially done on the super- computing system in the Supercomputing Center of University of Science and Technology of China.
基金The National Natural Science Foundation of China is gratefully acknowledged for financial support under grantNo.50674026
文摘The FFC Cambridge process is a direct electrodeoxidation process used to reduce metal oxides for metals or alloys in molten salts. Al-Sc compound oxides are used as a precursor which formed upon blending and sintering Al2O3, Sc2O3 and AI powders and are successfully reduced by using the FFC Cambridge process at 973 K with a constant cell voltage of -3.2 V. This method is applied to the preparation of fine Al3Sc particles, which can give another new view for aluminum industry.
基金Project supported by the National Natural Science Foundation of China (50472104 60478025)
文摘Gd3Sc2Ga3O12 polycrystalline material for single crystal growth was prepared with Ga, Gd2O3 and Sc2O3 as starting materials and aqueous ammonia as the precipitator by co-precipitation method. The precursors sintered at various temperatures were characterized by infrared spectra （IR）, X-ray diffractometry （XRD） and transmitted electron microscopy （TEM）. The results showed that pure GSGG phase could be obtained at 900 ℃. The sintered powders were well-dispersed and less-aggregated in the sintered temperature range of 900 - 1000 ℃. XRD and TEM show that the polycrystalline particle sizes of the polycrystalline powders were about 20 - 50 nm. Compared with the method that Ga2O3, Gd2O3 and Sc2O3 were mixed directly and sintered to get polycrystalline materials, the synthesized temperature was lower and sintered time was shorter. Thus co-precipitation was a good method to synthesize GSGG polycrystalline material.
基金supported by Ministry of Science and Higher Education (N N507 372335)
文摘Absorption, excitation and emission spectra as well as decay time measurements at 10, 77, and 300 K were perfumed for Gd3Sc2Ga3O12 garnet single-crystal doped with Cr^3＋ and Nd^3＋ ions. Strong reabsorption of Cr3＋ emission by Nd3＋ absorption lines was ob- served. The assignments of f-f and d-d transitions were proposed. The broad emission band of chromium ions is an indication that weak/intermediate crystal field strength is present at the Cr3＋ site.
基金Project was supported bythe National Natural Science Foundation of China (50372034 ,50323006)
文摘Single crystal of cobalt (Co)-doped Y3Sc2Ga3O12 (YSGG) with the dimensions up to Φ20×40 mm3 and undoped YSGG crystal with the dimensions up to Φ28×60 mm3 have been grown using the Czochralski technique. The structure of the crystal was characterized by the X-ray powder diffraction (XRPD) method. The absorbance spectra of the crystal shows that it has strong absorption bands at 606 and 1540 nm. The results indicate that the crystal Y3Sc2Ga3O12 may be a kind of good Q-switch material.
基金the Hunan Provincial Natural Science Foundation of China （No. 07JJ3117）Chinese Postdoctoral Scientific Foundation （No. 20070410303）.
文摘The ab initio method has been performed to explore the elastic and optical properties of Al3Sc compound, based on a plane wave pseudopotential method. It can be seen that the calculated equilibrium lattice parameter and elastic constants are in reasonable agreement with the previous experimental data. The elastic constants satisfy the requirement for mechanical stability in the cubic structure of the Al3Sc compound. The optical property calculations show that a strong absorptive peak exists from O-15eV and a relative small absorptive peak exists around 30eV. The form is caused by the optical transitions between high s, p, and d bands, and the latter results from the optical transitions from high s, p, and d bands to the low 2p band.
基金financially supported by the National Key R&D Program of China(No.2017YFB0405901)。
文摘Al-Sc alloys with high Sc contents are served as sputtering targets for making high-performance piezoelectric devices.The micro structure of these alloys would affect the sputtering process and the final quality of the functional devices.In this study,the microstructure in as-c as ted Al-20%Sc(in atomic ratio)alloys is characterized and the feathery Al3Sc grains with twin relationships are reported for the first time.The crystallographic features of twined structures and growth directions are quantitatively analyzed by electron backscatter diffraction(EBSD)technique.
基金National Natural Science Foundation of China(Nos.52001140,52274363)Guangdong Basic Applied Basic Research Foundation,China(Nos.2022A1515010558,2022A1515011597,2022A1515240065)。
