A study of the magnetocrystalline anisotropy of RFe_11-xCo_xTi compounds with R = Y and Er

Abstract

Structural and magnetic properties of the RFe11-xCoxTi compounds with R = Y and Er have been investigated. X-ray diffraction patterns and thermomagnetic curves show that all the synthesized compounds with x ranging from 0 to 11.0 are almost single phase and crystallize in the ThMn12-type structure. Substitution of Co for Fe leads to a monotonic decrease of lattice constants and unit-cell volume and a clear increase of the Curie temperature. The saturation moments increase with increasing Co content, going through a maximum at around x = 2.5, and then decrease with further increasing Co content. The easy magnetization direction (EMD) at room temperature for ErFe11-xCoxTi compounds is along the c-axis for x⩽4, perpendicular to the c-axis for 6⩽x⩽9 and then back to the c-axis for further increasing x. The anisotropy of the YFe11-xCoxTi compounds shows a similar behaviour. This concentration dependence of the magnetocrystalline anisotropy in the YFe11-xCoxTi and ErFe11-xCoxTi compounds results from the different contributions to the magnetocrystalline anisotropy from various transition-metal sites and the preferential occupation of Co atoms. A spin reorientation occurs below the Curie temperature for all ErFe11-xCoxTi compounds. Spin reorientation temperatures as a function of Co concentration were derived. A tentative spin phase diagram is given for ErFe11-xCoxTi compounds and can be understood in terms of crystal field theory.

Intrinsic magnetic properties inR(Fe1−xCox)11TiZ(R=Ke1, Johnson2 2016Phys. Rev. B443120View full textAdd to dashboardCite

“…The maximum magnetization occurs at x=0.2, while in experiments it is at x=0.3. [19] Similarly, for Ce(Fe 1−x Co x ) 11 Ti, the experimental maximum magnetization occurs at x=0.1−0.15. [55] As shown in Table II T C than the corresponding RFe 11 Ti compounds, which agrees with experiments.…”

“…[17] The largest magnetization in Y(Fe 1−x Co x ) 11 Ti occurs at YFe 8 Co 3 Ti while the T C increases continuously with Co composition until it reaches the maximum in YCo 11 Ti. [18,19] For Ce compounds, the maximum T C is obtained in CeFe 2 Co 9 Ti. [17] The dependence of MAE on the Co composition in R(Fe 1−x Co x ) 11 Ti is more intriguing and not understood.…”

“…For the intermediate Co composition, anisotropy changes from uniaxial to planar and then back to uniaxial with the increase of Co composition in both of Y(Fe 1−x Co x ) 11 Ti and Ce(Fe 1−x Co x ) 11 Ti. [17][18][19][20][21][22][23] The interstitial doping with H, [15] N [5,24,25] and C [26][27][28] can increase M and T C , and provide control of the magnitude and sign of the MAE constants in RFe 11 Ti. Hydrogenation simultaneously increases all three intrinsic magnetic properties in YFe 11 Ti, and enhancements are ∆M =1 µ B /f.u.…”

Effect of hydrogen insertion on the magnetic properties of Er(Fe,Co)11Ti single crystals

“…The hydrogen atoms in the ThMn 12 -type structure occupy only the 2b crystallographic sites. The intrinsic magnetic properties of Er(Fe,Co) 11 ples [10,11]. The aim of the present work is to study the effect of hydrogen insertion on MCA and SRT values of Er(Fe,Co) 11 Ti single crystals.…”

“…Further investigations of the SRT are necessary for understanding these phenomena in the rare-earth intermetallic compounds and their hydride phases. The magnetic properties of iron-rich rareearth intermetallic RFe 11 Ti and compounds with the tetragonal ThMn 12 -type structure (space group I4/mmm) have been investigated recently [1][2][3]. It is interesting to note that the in- * Corresponding author.…”