Effect of nitrogenation on the magnetic properties of Y2Fe17−xMx compounds, with M = Al, Ga or Si

Structural, Magnetic, and Mössbauer Studies of Transition Metal-Doped Gd2Fe16Ga0.5TM0.5 Intermetallic Compounds (TM = Cr, Mn, Co, Ni, Cu, and Zn)

“…The negative exchange interaction can be reduced either by volume expansion or by reducing the number of Fe-Fe pairs with negative exchange interactions. The low T C observed in parent Gd 2 Fe 17 compound is believed to be due to the short Fe-Fe interatomic distances found at the 4f (6c) sites in the hexagonal (rhombohedral) structure, which couple antiferromagnetically since their separation is~2.4 Å (Figure 3), which is less than 2.45 Å needed for ferromagnetic ordering [38].…”

“…Magnetochemistry 2018, 4, x FOR PEER REVIEW 9 of 17 separation is ~2.4 Å (Figure 3), which is less than 2.45 Å needed for ferromagnetic ordering [38]. It is to be noted that the increase in Tc has been reported earlier with higher Al, Ga, and Si content (at x > 2) in R2Fe17−xMx (M = Al, Ga, and Si) [15] but with a concomitant reduction in Ms due to large Fe replacement with non-magnetic atoms.…”

X-ray and intrinsic magnetic properties of nanocrystalline Sm2(Fe,M)17 (M = Si, Ga, Co, Cr, Zr or Mo)

“…The reason for the low T C is that some of the FeeFe distances are less than the critical value of 2.45 Å needed for ferromagnetic exchange interaction [1,2]. The rare earth sublattice anisotropy originates mainly from the crystalline electric field acting on 4f orbital which is axial for Sm but the resulting anisotropy of R 2 Fe 17 compounds is smaller since R sublattice is weaker in magnitude compared to Fe sublattice one thereby leading to planar anisotropy.…”

Effect of refractory metals addition on the structural and magnetic properties of Pr3(Fe, Co, Ti)29 system

“…Of these, Fe-Fe interaction which is the strongest plays an important role in determining the T C . There is a positive exchange interaction between the Fe-Fe atoms when the bond length between them is 42.45 Å and negative exchange interaction when the bond length iso2.45 Å [15]. An enhancement in T C was observed with increase of Co substitution for Fe in Pr 3 (Fe 1Àx Co x ) 27.5 Ti 1.5 [2] and Sm 3 Fe 28.1Àx Co x Mo 0.9 [16].…”