Nowadays,magnetic cooling(MC) technology by using the magnetocaloric effect(MCE) has attracted extensive research interest for its promising practical applications.A constant large/giant MCE covers wide refrigeration ...Nowadays,magnetic cooling(MC) technology by using the magnetocaloric effect(MCE) has attracted extensive research interest for its promising practical applications.A constant large/giant MCE covers wide refrigeration temperatures(denote as table-like shape) is beneficial for obtaining high efficiency performance for MC.In this paper,the HoNi/HoNi2 composite was successfully synthesized by arc-melting method and proved to be composed of HoNi and HoNi2 crystalline phases with weight ratios of 52.4 wt.% and 47.6 wt.%,respectively.The maximum magnetic entropy change(-ΔSMmax)is 18.23 J/(kg·K),and the refrigerant capacity values RC1,RC2,and RC3 are 867.9 J/kg,676.4 J/kg,and 467.8 J/kg with ΔH=0-70 kOe,respectively.The table-like shape MCE and large refrigerant capacity values make the composite attractive for cryogenic MC using the Ericsson cycle.展开更多
In this study,zirconium(Zr) successfully substituted for erbium(Er) in Er_(6-x)Zr_(x)MnSb_(2)(x=0,0.5,1,1.5) of the Fe_(2)P type,with comprehensive characterizations on crystal structure,electronic structure and magne...In this study,zirconium(Zr) successfully substituted for erbium(Er) in Er_(6-x)Zr_(x)MnSb_(2)(x=0,0.5,1,1.5) of the Fe_(2)P type,with comprehensive characterizations on crystal structure,electronic structure and magnetic properties.According to synchrotron powder X-ray diffraction data analysis and density functional theory calculation,Zr does not randomly but preferentially occupy during the doping process and results in weaker magnetic exchange interactions and depressed ordering temperatures.The electronic structure data show that the doping of Zr can weaken interaction between Er and Mn atoms.Owing to multiple transitions,the Er_(6-x)Zr_(x)MnSb_(2)(x=0,0.5,1,1.5) exhibit table-like magnetocaloric effect.Er_(6)MnSb_(2) displays wide δT_(FWHM)(full width at half maximum of the magnetic entropy change curve) of 116 K and high relative cooling power of 388.62 J/kg for 3 T.The maximum magnetic entropy change of Er_(6-x)Zr_(x)MnSb_(2) is increased from 3.81 to 7.69 J/(kg·K) with the Zr content up from x=0 to x=1.5.展开更多
Composite magnetic refrigerants were prepared by physical mixing LaFeSiHalloys with different Curie temperatures(Tc). The phase structures of these LaFeSiHalloys were analyzed by X-ray diffraction(XRD) and the magneto...Composite magnetic refrigerants were prepared by physical mixing LaFeSiHalloys with different Curie temperatures(Tc). The phase structures of these LaFeSiHalloys were analyzed by X-ray diffraction(XRD) and the magnetocaloric effect(MCE) and refrigerant capacity(RC) of these composite magnetic refrigerants were investigated by experiment and calculation in this paper. The magnetocaloric effect(MCE) and refrigerant capacity(RC) of these composite magnetic refrigerants were investigated by experiment and calculation in this paper. The results indicate the experimental magnetic entropy change(-△S)-Tcurve corresponds reasonably with the(-△S)-Tcurve calculated by the linear combination of(-△S)-T curves of the single material. An optimal mixing ratio can make the composite magnetic refrigerant possess a table-like(-△S)-Tcurve which is beneficial to magnetic Ericsson cycle. When three LaFeSiHalloys with different Tare mixed, the full width at half maximum(△T) of(-△S)-T curves is about 48.7 K and the RC is about 177.76 J/kg under a magnetic field change of 2 T. The composite magnetic refrigerants based on LaFeSiHalloys can be promising candidates for near room temperature magnetic refrigeration and the work will be helpful to develop novel composite magnetic refrigerants with table-like MCE and large RC.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.51690162)Science and Technology Committee of Shanghai,China(Grant No.19ZR1418300)+1 种基金Independent Research and Development Project of State Key Laboratory of Advanced Special Steel,Shanghai Key Laboratory of Advanced Ferrometallurgy,Shanghai University(Grant No.SKLASS 2019-Z003)the Science and Technology Commission of Shanghai Municipality,China(Grant No.19DZ2270200).
文摘Nowadays,magnetic cooling(MC) technology by using the magnetocaloric effect(MCE) has attracted extensive research interest for its promising practical applications.A constant large/giant MCE covers wide refrigeration temperatures(denote as table-like shape) is beneficial for obtaining high efficiency performance for MC.In this paper,the HoNi/HoNi2 composite was successfully synthesized by arc-melting method and proved to be composed of HoNi and HoNi2 crystalline phases with weight ratios of 52.4 wt.% and 47.6 wt.%,respectively.The maximum magnetic entropy change(-ΔSMmax)is 18.23 J/(kg·K),and the refrigerant capacity values RC1,RC2,and RC3 are 867.9 J/kg,676.4 J/kg,and 467.8 J/kg with ΔH=0-70 kOe,respectively.The table-like shape MCE and large refrigerant capacity values make the composite attractive for cryogenic MC using the Ericsson cycle.
基金Project supported by the National Natural Science Foundation of China (51861003)the Research Grants Council of Hong Kong(17208120)。
文摘In this study,zirconium(Zr) successfully substituted for erbium(Er) in Er_(6-x)Zr_(x)MnSb_(2)(x=0,0.5,1,1.5) of the Fe_(2)P type,with comprehensive characterizations on crystal structure,electronic structure and magnetic properties.According to synchrotron powder X-ray diffraction data analysis and density functional theory calculation,Zr does not randomly but preferentially occupy during the doping process and results in weaker magnetic exchange interactions and depressed ordering temperatures.The electronic structure data show that the doping of Zr can weaken interaction between Er and Mn atoms.Owing to multiple transitions,the Er_(6-x)Zr_(x)MnSb_(2)(x=0,0.5,1,1.5) exhibit table-like magnetocaloric effect.Er_(6)MnSb_(2) displays wide δT_(FWHM)(full width at half maximum of the magnetic entropy change curve) of 116 K and high relative cooling power of 388.62 J/kg for 3 T.The maximum magnetic entropy change of Er_(6-x)Zr_(x)MnSb_(2) is increased from 3.81 to 7.69 J/(kg·K) with the Zr content up from x=0 to x=1.5.
基金supported by the Key Project of National Natural Science Foundation of China(51176065)
文摘Composite magnetic refrigerants were prepared by physical mixing LaFeSiHalloys with different Curie temperatures(Tc). The phase structures of these LaFeSiHalloys were analyzed by X-ray diffraction(XRD) and the magnetocaloric effect(MCE) and refrigerant capacity(RC) of these composite magnetic refrigerants were investigated by experiment and calculation in this paper. The magnetocaloric effect(MCE) and refrigerant capacity(RC) of these composite magnetic refrigerants were investigated by experiment and calculation in this paper. The results indicate the experimental magnetic entropy change(-△S)-Tcurve corresponds reasonably with the(-△S)-Tcurve calculated by the linear combination of(-△S)-T curves of the single material. An optimal mixing ratio can make the composite magnetic refrigerant possess a table-like(-△S)-Tcurve which is beneficial to magnetic Ericsson cycle. When three LaFeSiHalloys with different Tare mixed, the full width at half maximum(△T) of(-△S)-T curves is about 48.7 K and the RC is about 177.76 J/kg under a magnetic field change of 2 T. The composite magnetic refrigerants based on LaFeSiHalloys can be promising candidates for near room temperature magnetic refrigeration and the work will be helpful to develop novel composite magnetic refrigerants with table-like MCE and large RC.