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

• Published in: Solid state communications 2022-11, Vol.355, p.114922, Article 114922
• Main Authors: Benea, D., Hirian, R., Gutoiu, S., Isnard, O., Pop, V.
• Format: Article
• Language: English
• Subjects: A. ab-initio calculations; B. magneto-crystalline anisotropy; C. magnetization; D. rare earth magnets; Physics
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2022.114922

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. •Intrinsic magnetic properties of RFe11-xCoxTiCz (x = 0–3, z = 1) and R1-yZryFe11Ti(y = 0.1) for R = Y, Gd.•Co preferential occupation for 8j and 8f sites determined by total energy calculations.•Increase of Fe spin moments and Tc by Co doping found for both RFe11-xCoxTi alloys, R = Y and Gd.•The site-dependent MAE evolutions by Co, Zr and C doping are analysed.•Minor impact on intrinsic properties induced by Zr doping, on opposite to C addition.