Synthesis Of Heusler Alloy Fe₂Nin And Co₂NiSn By Electrodeposition

Heusler alloys of X₂YZ type have received widespread attention owing to their diversity in structural and physical properties..Thin films Fe₂NiSn of Heusler alloys were successfully prepared by an electrochemical deposition method on Cu substrates and ITO substrates,respectively.The effect of concentration ratio of plating bath metal ions,pH of the plating bath,deposition time and cathode current density on the deposited layer composition,phase structure and surface topography has been examined,also the magnetic of Fe₂NiSn was studied.In the mean time,we studied the conditions that make thin films Co₂NiSn of Heusler alloys on Cu substrates by electrochemical deposition.This will have an important significance to the development of the new type of Heusler alloys and the research of its physical properties.Experimental results show that:the abnormal Co-deposition phenomenon will appeared on Ni and,when we made the thin films Fe₂NiSn of Heusler alloys on Cu substrates.When the cathode current density is greater than 3 A/dm²,and the deposition time is 10-30 min,the Ni2FeSn alloy crystalizes in cubic phase.When the current density is 3 A/dm²,the deposition time is more than 20 min,here appeared Sn,Sn increases with the increase of the current density,Ni conversely.Fe is increased with the pH of the solution increased,but Sn content is reduced.We found that the experimental with the condition that the concentration ratio of plating bath metal ions is Fe i Ni:Sn =0.05:0.075:0.0083,pH = 7.0,T = 60?,the deposition t = 15 min,cathode current density is 3A/dm²,the Fe-Ni-Sn alloy crystalizes in cubic phase both on Cu and ITO substrates.And here Fe content get increased,Ni and Sn conversely.The deposition time has increased from 5min when we made the Fe₂NiSn on ITO,but not changed amount.Finally,we got the best conditions that experiment on the Cu:the concentration ratio of plating bath metal ions is FeSO₄·7H₂O?0.05 M?,NiSO₄·6H₂O?0.075 M?,SnSO₄?0.0083 M?,pH = 7.0,T = 60?,the deposition t =15 min,cathode current density is 3 A/dm².And we got the best conditions that experiment on the ITO:the concentration ratio of plating bath metal ions is FeSO₄·6H₂O?0.05 M?,NiSO₄·6H₂O?0.075 M?,SnSO₄?0.0083 M?,pH = 7.0,T = 60?,the deposition t = 5 min,cathode current density of 2.5 A/dm².We made the thin films Co₂NiSn by electrochemical deposition.It is found that:when the current density is less than 0.5 A/dm²,plating layer appeared Co-Ni-Sn alloy as Body-centered cubic phase,and the diffraction peaks of Co-Sn alloy appeared on 30 min.The content of Sn increased with increasing of the deposition time while Ni content decreased.