Intrinsic magnetic properties of the RFe11Ti (R = Y and Gd) alloys by Co, Zr and C doping

We present theoretical investigations on the electronic and magnetic properties of the RFe11-xCoxTiCz and R1-yZryFe11Ti (R = Y and Gd; x = 0-3, y = 0-0.1, z = 0 and 1) alloys describing the dependence of the magnetic properties (magnetic moments, magneto-crystalline anisotropy, exchange-coupling parameters and Curie temperatures) on the R/Zr and Fe/Co ratios and by C addition. According to our calculations for YFe11-xCoxTi, the total magnetic moment and magnetocrystalline anisotropy energy (MAE) are maximized for x = 1. On the other hand, Co doping enhances the MAE but reduces the total magnetic moment in GdFe11-xCoxTi alloys. The doping adding one C atom to the near-neighbour environment of Fe 8j site affects the magnetic moments of Fe changing their magnitude sequence. Also, Zr for R substitution and C addition have lower impact on MAE, compared with Co for Fe substitution in RFe11Ti-type alloys. The calculated exchange-coupling parameters show highest values between Fe 8i spins, followed by Fe 8i - Fe 8j spins for all investigated alloys. The corresponding mean-field approach estimated Curie temperatures show qualitative agreement with available experimental data.

Automated summary

This study presents theoretical investigations on the electronic and magnetic properties of RFe11-xCoxTiCz and R1-yZryFe11Ti alloys. The results show that the magnetic properties of the alloys depend on the R/Zr and Fe/Co ratios as well as C addition. Specifically, in YFe11-xCoxTi alloys, the total magnetic moment and magnetocrystalline anisotropy energy (MAE) are maximized when x = 1. On the other hand, Co doping enhances the MAE but reduces the total magnetic moment in GdFe11-xCoxTi alloys.