Through magnetization measurement with a SQUID magnetometer the heat treatment optimization of an international thermonuclear experimental reactor （ITER）-type internal-Sn Nb3Sn superconducting wire has been investig...Through magnetization measurement with a SQUID magnetometer the heat treatment optimization of an international thermonuclear experimental reactor （ITER）-type internal-Sn Nb3Sn superconducting wire has been investigated. The irreversibility temperature T^＊ （H）, which is mainly dependent on A15 phase composition, was obtained by a warming and cooling cycle at a fixed field. The hysteresis width △M（H） which reflects the flux pinning situation of the A15 phase is determined by the sweeping of magnetic field at a constant temperature. The results obtained from differently heat-treated samples show that the combination of T^＊ （H） with AM（H） measurement is very effective for optimizing the heat reaction process. The heat treatment condition of the ITER-type wire is optimized at 675℃/128 h, which results in a composition closer to stoichiometric Nb3Sn and a state with best flux pinning.展开更多
Prisms-built VO_(2)(M)micro-nanostructures with narrow hysteresis width of 2.7℃were successfully synthesized using V_(2)O_(5)-H_(2)C_(2)O_(4)-H2O system by one-pot hydrothermal approach.The structure,composition,phas...Prisms-built VO_(2)(M)micro-nanostructures with narrow hysteresis width of 2.7℃were successfully synthesized using V_(2)O_(5)-H_(2)C_(2)O_(4)-H2O system by one-pot hydrothermal approach.The structure,composition,phase transition and optical properties were characterized by XRD,SEM,DSC,and variable-temperature UV-vis.The results revealed the prism had well-defined six facets and entire smooth surface with lengths of about 500 nm and thicknesses of around 100 nm.Several prisms were connected to each other through the apical growth.The prismatic VO_(2)(M)showed excellent phase transition and optical switching properties that would be beneficial for highly sensitive electrical/optical devices or other applications.The possible formation mechanism of prismatic VO_(2)(M)was proposed via time-dependent SEM images and XRD patterns.Furthermore,the influence of the amount of H_(2)O on the final product was discussed in detail.展开更多
文摘Through magnetization measurement with a SQUID magnetometer the heat treatment optimization of an international thermonuclear experimental reactor （ITER）-type internal-Sn Nb3Sn superconducting wire has been investigated. The irreversibility temperature T^＊ （H）, which is mainly dependent on A15 phase composition, was obtained by a warming and cooling cycle at a fixed field. The hysteresis width △M（H） which reflects the flux pinning situation of the A15 phase is determined by the sweeping of magnetic field at a constant temperature. The results obtained from differently heat-treated samples show that the combination of T^＊ （H） with AM（H） measurement is very effective for optimizing the heat reaction process. The heat treatment condition of the ITER-type wire is optimized at 675℃/128 h, which results in a composition closer to stoichiometric Nb3Sn and a state with best flux pinning.
基金supported by the Hubei Provincial Department of Education(B2020129)Scientific Research Foundation(HS2020RC021)。
文摘Prisms-built VO_(2)(M)micro-nanostructures with narrow hysteresis width of 2.7℃were successfully synthesized using V_(2)O_(5)-H_(2)C_(2)O_(4)-H2O system by one-pot hydrothermal approach.The structure,composition,phase transition and optical properties were characterized by XRD,SEM,DSC,and variable-temperature UV-vis.The results revealed the prism had well-defined six facets and entire smooth surface with lengths of about 500 nm and thicknesses of around 100 nm.Several prisms were connected to each other through the apical growth.The prismatic VO_(2)(M)showed excellent phase transition and optical switching properties that would be beneficial for highly sensitive electrical/optical devices or other applications.The possible formation mechanism of prismatic VO_(2)(M)was proposed via time-dependent SEM images and XRD patterns.Furthermore,the influence of the amount of H_(2)O on the final product was discussed in detail.
