Investigation on the 773K isothermal section of Ho-Ni-Si ternary phase diagram by X-ray powder diffraction and magnetic property of Ho₃NiSi₂ alloy

Xiang Chen^1,2，Jixin Gong¹，Jiaojiao Luo¹，Wenxuan Yang¹，Xian Qing¹

1. The college of Physics and Electronic Information Engineering,Neijiang Normal University2. The Ames Laboratory,U.S.Department of Energy,Iowa State University

摘 要：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 Ho_33.3Ni_18.7-9.7Si_-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 T_SR=10 K and a second order ferromagnetic（FM）-paramagnetic（PM）transition at T_c=37 K.

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