Understanding the complex magentism in Ce₂Fe₁₇ from ab initio methods

The high magnetization and the low costs have made the intermetallic Ce₂Fe₁₇ an attractive candidate for permanent magnets. Its low Curie temperature (T_C) and basal plane magnetocrystalline anisotropy can be cured by doping with light elements. Despite this no full understanding of the magnetism of Ce₂Fe₁₇ has been achieved so far. Though a large number of partially seemingly contradicting findings exist theoretical studies are sparse and do not capture the experimental findings. We have performed a comprehensive study of the magnetism of Ce₂Fe₁₇ investigating carefully the best theoretical treatment of the system e.g. by applying  various approaches for the exchange-correlation functional. To account for the mixed valent nature of Ce₂Fe₁₇ several approximations were tested including an analysis of the hybridization function as proposed in [1]. We used a combination of ab initio codes  to obtain structural and magnetic data including magnetic exchange parameters. The later were used in Monte Carlo simulations [4] to determine T_C.

Our results clearly show [2]  that the ground state is  noncollinear with a strong FM component which explains the low magnetic moment reported in experiment. Furthermore,  the transition to the helical state turns out correctly from our investigations.