High quality and monodispersed ScVO4 microcrystals were successfully synthesized via a mild hydrothermal route using NH4VO3 as vanadium source. The X-ray power diffraction（XRD） and field-emission scanning electron m...High quality and monodispersed ScVO4 microcrystals were successfully synthesized via a mild hydrothermal route using NH4VO3 as vanadium source. The X-ray power diffraction（XRD） and field-emission scanning electron microscopy（FE-SEM） results indicated that the size, shape, and phase formation of the ScVO4 microcrystals could be tuned by altering the reaction temperature, reaction time, and p H value of the initial solution. Furthermore, the down- and upconversion luminescence of ScVO4：Ln（Ln=Eu, Dy, Sm, Yb/Ho, Yb/Er, and Yb/Tm） microcrystals were characterized and the respective energy transfer processes were also discussed. The experimental results demonstrated that reactions at 200 oC, 24 h, and pH=6 could generate perfect ScVO4 microcrystals, which were then used for luminescence studies.展开更多
The open-circuit photovoltage is improved by adding 1-hexyl-3-methylimidazolium iodide （HMImI） into the electrolyte. To investigate the mechanisms of the increase of the open-circuit photovoltage, we take the MottSc...The open-circuit photovoltage is improved by adding 1-hexyl-3-methylimidazolium iodide （HMImI） into the electrolyte. To investigate the mechanisms of the increase of the open-circuit photovoltage, we take the MottSchottky analysis and time-resolved mid-infrared absorption spectroscopy to study the band edge movement of TiO2 and the rate of back electron transfer, respectively. The results indicate that the negative shift of the conduction band of TiO2 is a predominant factor to increase the open-circuit photovoltage for the electrolyte containing HMImI,展开更多
Nickel-iron nanocrystalline alloys with different compositions and grain sizes were fabricated by electroplating for MEMS devices. The iron content of the deposits was changed by varying the nickel/iron ion ratio in t...Nickel-iron nanocrystalline alloys with different compositions and grain sizes were fabricated by electroplating for MEMS devices. The iron content of the deposits was changed by varying the nickel/iron ion ratio in the electrolyte. X-ray diffraction (XRD) analysis was applied for measuring the strength of the texture and grain size of the deposits. The nickel/iron atom ratio of the deposits was analyzed by EDS. The hardness of the alloys was evaluated by Vickers hardness indenter. The internal stress of the deposits was measured by thin film stress measurement using Stoney's formula. Surface morphology and roughness were investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Hardness and internal stress mechanism of the electroplated structure as a function of Fe ion content and current density were revealed. With increasing the iron content, the hardness and internal stress of the deposits increase. An excellent correlation between the increase in the internal stress and the loss of (200) texture were found.展开更多
基金Project supported by the National Natural Science Foundation of China(21371095)the Natural Science Foundation of Jiangsu Province(BK20131404,BL2014075)the Ministry of Education Doctoral Fund(20133221110004)
文摘High quality and monodispersed ScVO4 microcrystals were successfully synthesized via a mild hydrothermal route using NH4VO3 as vanadium source. The X-ray power diffraction（XRD） and field-emission scanning electron microscopy（FE-SEM） results indicated that the size, shape, and phase formation of the ScVO4 microcrystals could be tuned by altering the reaction temperature, reaction time, and p H value of the initial solution. Furthermore, the down- and upconversion luminescence of ScVO4：Ln（Ln=Eu, Dy, Sm, Yb/Ho, Yb/Er, and Yb/Tm） microcrystals were characterized and the respective energy transfer processes were also discussed. The experimental results demonstrated that reactions at 200 oC, 24 h, and pH=6 could generate perfect ScVO4 microcrystals, which were then used for luminescence studies.
基金Supported by the Major State Basic Research and Development Programme of China under Grant No G2000028205, the National High Technology Program of China under Grant No 2002AA302403, and the National Natural Science Foundation of China under Grant Nos 50221201 and 50473055.
文摘The open-circuit photovoltage is improved by adding 1-hexyl-3-methylimidazolium iodide （HMImI） into the electrolyte. To investigate the mechanisms of the increase of the open-circuit photovoltage, we take the MottSchottky analysis and time-resolved mid-infrared absorption spectroscopy to study the band edge movement of TiO2 and the rate of back electron transfer, respectively. The results indicate that the negative shift of the conduction band of TiO2 is a predominant factor to increase the open-circuit photovoltage for the electrolyte containing HMImI,
文摘Nickel-iron nanocrystalline alloys with different compositions and grain sizes were fabricated by electroplating for MEMS devices. The iron content of the deposits was changed by varying the nickel/iron ion ratio in the electrolyte. X-ray diffraction (XRD) analysis was applied for measuring the strength of the texture and grain size of the deposits. The nickel/iron atom ratio of the deposits was analyzed by EDS. The hardness of the alloys was evaluated by Vickers hardness indenter. The internal stress of the deposits was measured by thin film stress measurement using Stoney's formula. Surface morphology and roughness were investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Hardness and internal stress mechanism of the electroplated structure as a function of Fe ion content and current density were revealed. With increasing the iron content, the hardness and internal stress of the deposits increase. An excellent correlation between the increase in the internal stress and the loss of (200) texture were found.
