The isothermal section of the Ho-Ni-Si system at 773 K was constructed by X-ray powder diffraction(XRD)in this work.The system contains sixteen known type structure compounds TiNiSi-type HoNiSi,BaAl4-type HoNi2Si2,CeN...The isothermal section of the Ho-Ni-Si system at 773 K was constructed by X-ray powder diffraction(XRD)in this work.The system contains sixteen known type structure compounds TiNiSi-type HoNiSi,BaAl4-type HoNi2Si2,CeNiSi2-type HoNiSi2,U1Co3Si5-type Ho2Ni3Si5,SmNiGe3-type HoNiSi3,Ce3 Ni6Si2-type Ho3Ni6Si2,ThMn12-type HoNi10Si2,YPd2Si-type HoNi2Si,YNi5Si3-type HoNi5Si3,YNi4Si-type HoNi4Si,Gd3NiSi2-type Ho3NiSi2,YNi6Si6-type HoNi6Si6.AlB2-type Ho2NiSi3,AlB2-type Ho3Ni2Si4,AlB2-type Ho4NiSi7,Gd3Ru4Al12-type Ho8Ni31Si11,and one unknown type structure compound Ho5Ni2Si3.At the same time,one unknown structure new phase Ho37Ni3Si60 was observed.In ternary compounds,Ho2NiSi3 and Ho4NiSi7 have the solid solution phenomena;the solid solution ranges are about Ho33.3Ni18.7-9.7Si-48.0-57.0 and Ho33.Ni-8.3-2.6Si-58.3-64.1,respectively.At the same time,quasi-binary solid solutions were detected at 773 K for Ho2Ni17,HoNi5,Ho2Ni7,HoNi3,HoNi2,HoNi,HoSi.Other binary compounds of the Ho-Ni-Si system do not show any visible solubility.The magnetic property studies show that Ho3NiSi2 compound has two successive magnetic phase transitions in a low field:a spinreorientation transition at TSR=10 K and a second order ferromagnetic(FM)-paramagnetic(PM)transition at Tc=37 K.展开更多
The isothermal section of the Ho-Fe-In system at 773 K has been constructed by X-ray powder diffraction.One known structure ternary compound Er_(12)Fe_(2) In_(3)-type Ho_(12)Fe_(2) In_(3) has been confirmed.At the sam...The isothermal section of the Ho-Fe-In system at 773 K has been constructed by X-ray powder diffraction.One known structure ternary compound Er_(12)Fe_(2) In_(3)-type Ho_(12)Fe_(2) In_(3) has been confirmed.At the same time,solid solutions are not detected in Ho-Fe-In system at 773 K.The magnetic transition and magnetocaloric effect of Ho_(12)Fe_(2.08)In_(2.92) alloy with Er_(12)Fe_(2) In_(3)-type structure were investigated by magnetic susceptibility and isothermal magnetization measurements.One normal antiferromagnetic-paramagnetic transition and another abnormal one are discovered at 18 and 76 K in ground state,respectively.Owing to a first-order field-induced metamagnetic transition(antiferromagnetic-ferromagnetic) at/below the Neel temperature of 18 K),the negative entropy changes are observed at corresponding temperature.There is only a second-order ferromagnetic-paramagnetic transition near Curie temperature(TC),the maximum entropy change(Δ_(Smax)) values are-6.14 J·kg^(-1)·K^(-1) at 3 K and 7.88 J·kg^(-1)·K^(-1) at 28 K in a field range of 0-7 T.The reversible relative cooling power corresponding to negative entropy change can reach about 600 J·kg^(-1) in an wide operating temperature region Δ_(Tcycl)=74 K from 16 to90 K,which suggests that Ho_(12)Fe_(2.08)In_(2.92) could be a potential material for magnetic refrigeration in the corresponding temperature range.展开更多
基金Project supported by the Department of Science and Technology of Sichuan Province in China(2017JY0181)。
文摘The isothermal section of the Ho-Ni-Si system at 773 K was constructed by X-ray powder diffraction(XRD)in this work.The system contains sixteen known type structure compounds TiNiSi-type HoNiSi,BaAl4-type HoNi2Si2,CeNiSi2-type HoNiSi2,U1Co3Si5-type Ho2Ni3Si5,SmNiGe3-type HoNiSi3,Ce3 Ni6Si2-type Ho3Ni6Si2,ThMn12-type HoNi10Si2,YPd2Si-type HoNi2Si,YNi5Si3-type HoNi5Si3,YNi4Si-type HoNi4Si,Gd3NiSi2-type Ho3NiSi2,YNi6Si6-type HoNi6Si6.AlB2-type Ho2NiSi3,AlB2-type Ho3Ni2Si4,AlB2-type Ho4NiSi7,Gd3Ru4Al12-type Ho8Ni31Si11,and one unknown type structure compound Ho5Ni2Si3.At the same time,one unknown structure new phase Ho37Ni3Si60 was observed.In ternary compounds,Ho2NiSi3 and Ho4NiSi7 have the solid solution phenomena;the solid solution ranges are about Ho33.3Ni18.7-9.7Si-48.0-57.0 and Ho33.Ni-8.3-2.6Si-58.3-64.1,respectively.At the same time,quasi-binary solid solutions were detected at 773 K for Ho2Ni17,HoNi5,Ho2Ni7,HoNi3,HoNi2,HoNi,HoSi.Other binary compounds of the Ho-Ni-Si system do not show any visible solubility.The magnetic property studies show that Ho3NiSi2 compound has two successive magnetic phase transitions in a low field:a spinreorientation transition at TSR=10 K and a second order ferromagnetic(FM)-paramagnetic(PM)transition at Tc=37 K.
基金financially supported by the Department of Science and Technology of Sichuan Province in China(No.2017JY0181)。
文摘The isothermal section of the Ho-Fe-In system at 773 K has been constructed by X-ray powder diffraction.One known structure ternary compound Er_(12)Fe_(2) In_(3)-type Ho_(12)Fe_(2) In_(3) has been confirmed.At the same time,solid solutions are not detected in Ho-Fe-In system at 773 K.The magnetic transition and magnetocaloric effect of Ho_(12)Fe_(2.08)In_(2.92) alloy with Er_(12)Fe_(2) In_(3)-type structure were investigated by magnetic susceptibility and isothermal magnetization measurements.One normal antiferromagnetic-paramagnetic transition and another abnormal one are discovered at 18 and 76 K in ground state,respectively.Owing to a first-order field-induced metamagnetic transition(antiferromagnetic-ferromagnetic) at/below the Neel temperature of 18 K),the negative entropy changes are observed at corresponding temperature.There is only a second-order ferromagnetic-paramagnetic transition near Curie temperature(TC),the maximum entropy change(Δ_(Smax)) values are-6.14 J·kg^(-1)·K^(-1) at 3 K and 7.88 J·kg^(-1)·K^(-1) at 28 K in a field range of 0-7 T.The reversible relative cooling power corresponding to negative entropy change can reach about 600 J·kg^(-1) in an wide operating temperature region Δ_(Tcycl)=74 K from 16 to90 K,which suggests that Ho_(12)Fe_(2.08)In_(2.92) could be a potential material for magnetic refrigeration in the corresponding temperature range.
