Magnetic ordering in ErFe₆Sn₆

Abstract

We have determined the magnetic structures of the Er and Fe sublattices in ErFe 6 Sn 6 by high-resolution neutron powder diffraction and Mössbauer spectroscopy on the 166 Er, 57 Fe and 119 Sn isotopes. The crystal space group is orthorhombic Cmcm. The Fe sublattice is antiferromagnetic with a Néel temperature of 560(5) K and it orders along the [100] direction with a magnetic space group C P m c m and a propagation vector [010]. The Fe magnetic moment at 1.5 K is 2.4 ± 0.6 µ B . The Er sublattice orders independently of the Fe sublattice at 4.8 ± 0.4 K and comprises a ferromagnetic mode along [100] and an antiferromagnetic mode along [010], with a propagation vector [0 1 2 0] i.e. cell-doubling along [010]. The magnetic space group of the Er sublattice within the magnetic unit cell is Pbc m , a subgroup of Cmcm. At 1.5 K the ferromagnetic and antiferromagnetic components of the Er 3+ magnetic moment (determined by a combination of neutron diffraction and magnetization measurements) are 5.9 ± 0.1 and 4.9 ± 1.5 µ B , respectively, yielding a net Er moment of 7.7 ± 1.5 µ B . The Er 3+ magnetic moment derived from 166 Er Mössbauer spectroscopy is 8.5(1) µ B .

Dependence of the Fe anisotropy on the Dy concentration in the DyxFe6Sn6 (0.3<x<1) compounds

“…No significant differences are observed between the zero-field cooled (ZFC) and field cooled (FC) curves, either. This agrees with the main antiferromagnetic coupling between the Fe atoms typical of FeSn and of all the A x Fe 6 X 6 whose magnetic structures are already established [7][8][9]15,19,22], as referred above. On the other hand M(T) curves of Dy 0.5 Fe 6 Sn 6 and DyFe 6 Sn 6 samples (Fig.…”

“…In the present DyFe 6 Sn 6 sample crystallizing in an orthorhombic superstructure of the hexagonal HfFe 6 Ge 6 -type, Fe is distributed in a large number of different crystallographic sites [13]. However as shown by Wang et al for AFe 6 Ge 6 (A = Y, Tb) and Cadogan et al for AFe 6 Sn 6 A = Y, Ho, Er [7,8,15,16], from the Mössbauer effect point of view the Fe sites in these superstructures of the hexagonal HfFe 6 Ge 6 -type may be treated as equivalent. The spectra may therefore be discussed in terms of the parent HfFe 6 Ge 6 -type structure.…”

“…In addition to potential applications as high-T C materials their extensive research was also justified from a fundamental point of view due to the unusual and interesting magnetic properties reported for some of them, namely AFe 4 Al 8 [1][2][3][4] and A x Fe 6 X 6 (X = Sn, Ge) [5][6][7][8][9][10].…”

Crystal structure, 57Fe Mössbauer spectroscopy and magnetization of UxFe6Sn6 (0≤x≤0.6)

“…The RFe 6 X 6 intermetallics (RZrare-earth, Sc, Zr and XZSn, Ge) have also been subject of extensive investigations [8][9][10][11][12][13][14][15]. In these intermetallics, there is a cancellation of the Fe-R exchange interactions at the R sites due to the local environment [9], as in the structurally closely related ThMn 12 -type AFe 4 Al 8 compounds [1].…”

Isothermal section of the Dy–Fe–Sn phase diagram at 800°C

“…These investigations have led to the discovery of unusual magnetic behaviours such as those found for AFe 4 Al 8 intermetallics [1][2][3]. One interesting property, the phenomenon of independent magnetic order whereby the A and T sublattices order at different temperatures and/or in orthogonal directions, was also observed in the A-Fe-T systems where T = Sn, Ge [4,5]. The physical properties of these intermetallics were found to be very sensitive to sample preparation, specifically to heat treatments, indicating an important role of homogeneity ranges and structural disorder [2,6].…”