Study On The Interaction Of Rare Earth Element Neodymium With Iron And Arsenic

Rare earth elements have a wide range of applications,and research on rare earths has been a very active topic all the time.However,there is a lack of research on rare earth neodymium,iron and arsenic at home and abroad.Therefore,this paper combines the research methods of physical chemistry in metallurgy and the organization,structure,and second phase study of metal materials.The effect of different proportion,temperature range and holding time on the interaction of the Nd-Fe-As ternary system was systematically studied.In this paper,the holding temperature?T=1173K,1223K,1273K?,the ratio of neodymium to arsenic?Nd:As=1.5:1,1:1:1,1:1.5?and the holding time?t=5h,30h,50h?are designed.The homemade H08 steel cylinders are used to load raw materials,which could isolate the air.The metallographic microscope,scanning electron microscope,energy dispersive spectrometer and X-ray diffraction analyzer are used for the test analysis to study the interaction of Nd-Fe-As system.It's found that NdAs,Fe₁₂As₅ and Fe are the products when the temperature was1173K;NdAs and Nd₂Fe₁₇7 were the products when the temperature was 1223K;NdAs,Fe₂As and Fe were the products when the temperature was 1273K.Increasing the holding temperature was beneficial to homogenization of high temperature products.When the atomic ratio of neodymium to arsenic is 1.5:1,the high temperature products are NdAs and Nd₂Fe_17;When the atomic ratio of neodymium to arsenic is 1:1,the high temperature products are NdAs,Nd₄Fe₆ and FeAs_2;When the atomic ratio of neodymium to arsenic is 1:1.5,the high temperature products are NdAs,Fe₂As and Fe.The atomic ratio of neodymium to arsenic has no effect on the distribution and homogeneity of the high temperature products of the sample.NdAs,FeAs₂,and Nd are the high temperature products when the holding time is 5 hours;NdAs,Fe₂As,Fe₁₂As₅,and Fe are the high temperature products when the holding time is 30 hours;NdAs and Nd₂Fe₁₇7 are high temperature products when the holding time is 50 hours.With the holding time changes,some of the compounds are converted to one another.As the holding time is extended,the homogeneity of the high temperature product is improved.When the holding time is 50 hours,the uniformity of the sample is relatively good.In the high temperature products of rare earth element neodymium,iron and arsenic,the existence of a phase with the atomic ratio of neodymium,iron,and arsenic close to 1:1:1 is found.It is initially judged as a ternary compound NdFeAs.