True magnetic structure of the ferrimagnetic garnet Y3Fe5O12 and magnetic moments of iron ions

Site occupancy and magnetic study of Al3+ and Cr3+ co-substituted Y3Fe5O12

“…However, the magnetic ordering of ferrites like YIG changes significantly from its arrangement at room temperature, as shown for x ¼ 0. 4 [11] for Y 3 Fe 5À2x Al x Cr x O 12 garnets would lead to magnetic moment inconsistent with that obtained from magnetization measurements reported in this study. In this work, three techniques, namely, X-ray diffraction, low temperature magnetization and Mö ssbauer spectroscopy, were employed to clarify the site preference of Cr 3+ and Al 3+ ions in Y 3 Fe 5À2x Al x Cr x O 12 garnets.…”

“…YIG has the chemical composition {Y 3 [3] and in the trigonal space group R3 by Rodic et al [4], to account for the lowering of symmetry due to spontaneous magnetostriction. YIG is ferrimagnetic with two magnetic a and d sublattices of Fe 3+ that are coupled antiparallelly.…”

Element selective X-ray magnetic circular and linear dichroisms in ferrimagnetic yttrium iron garnet films

“…Moreover, in ferrimagnetically ordered phases, the Curie principle as well as Landau's theory of phase transitions requires that the crystal symmetry can only be a subgroup of the paramagnetic (cubic) phase. In this paper, we shall produce X-ray linear dichroism data which confirm the existence of small structural distortions making rhombohedral subgroups more realistic such as R3 (S 6 ; group N 3 148) [26] in the ferrimagnetic phase, or R3m (C 3v ; group N 3 160) in the magnetoelectric phase [21].…”

“…It is our interpretation that such a dichroism can be observed because structural distortions tend to lower the symmetry of the crystal. For subgroups R3 or R3m [21,26] a linear dichroism should already be expected within the electric dipole transition approximation as soon as the X-ray wavevector is not parallel to the trigonal axis since Ds D ðe; kÞ ¼ 1 ffiffi 2 p ð1 À 3cos 2 yÞs D ð2; 0Þ ð 9Þ Indeed, Eq. (9) refers to new orthonormal axes, the z axis being taken along the trigonal symmetry axis (C 3 ).…”

The full magnon spectrum of yttrium iron garnet

“…It has been pointed out 24 that the magnetic structure of YIG is incompatible with the cubic crystal symmetry, although to date no measurements have found any evidence for departures from the ideal cubic structure. Nevertheless, it is necessary to refine the magnetic structure in a trigonal space group (a symmetry that is experimentally observed in terbium rare earth garnets where the magnetoelastic coupling is much stronger 25 ), in order to obtain a satisfactory goodness of fit, and a magnetic moment which agrees with bulk magnetometry.…”