Abstract
The Fe-Pt based intermetallic compounds exhibit good chemical stability and unique magnetic proper-ties,where Ni is an important additional element to optimize the magnetic properties or obtain the outstanding catalytic performances of the Fe-Pt based alloys.Knowledge of how Ni addition affects the order-disorder transitions of the Fe-Pt intermetallics is thus necessary;however,the related information is limited.Therefore,in this work,the phase diagrams of the Fe-Ni-Pt system were experimentally in-vestigated,and as a result,the isothermal sections of the Fe-Ni-Pt system at 600 and 900 ℃,as well as the vertical sections of Fe80Ni20-Pt80Ni20 and Fes0Pts0-Nis0Pts0 were constructed.Based on these re-sults,the influences of Ni addition on the crystal stabilities and phase transformations of the ordered Fe-Pt intermetallics have been well described.The results show that the L10-FePt and L10-NiPt phases form a ternary continuous solid solution of L10-(Fe,Ni)Pt,whereas Ni can dissolve in the L12-Fe3Pt and L12-FePt3 phases as high as 57.0 at.％and 26.0 at.％at 600 ℃,respectively.The selective occupancy of Ni atoms has been predicted,which should depend on the alloy composition.For both the L10-(Fe,Ni)Pt and L12-FePt3 phases,when Pt contents are less than their stoichiometric values,Ni atoms will preferentially occupy the Pt sublattice,forming as many nearest-neighbor Fe-Pt bonds as possible.All these results can correlate the alloy compositions,annealing temperatures and crystal structures to both magnetic and catalytic properties,thus providing a basis for optimizing the Fe-Ni-Pt alloys towards enhanced magnetic or catalytic performances.
基金项目
Major Scientific and Technological Projects in Yunnan Province(202002AB080001-1)
国家自然科学基金(U1602275)
国家自然科学基金(51971059)
NETL
NSTL
万方数据