Neutron scattering length of terbium structure refinement and magnetic moments of terbium iron garnet

Temperature Evolution of the Double Umbrella Magnetic Structure in Terbium Iron Garnet

“…The results lead to a good agreement between the bulk calculated magnetizations M S cal (TbIG) and the observed spontaneous magnetization M S obs (TbIG) (Pauthenet, 1958a(Pauthenet, , 1958b. The result at 283 K (1.15 μ B with R = 8.5 %) (Lahoubi, 1986) is similar to that found previously Fuess et al, 1976) but with a poor agreement for m a and m d which have been found lower by comparison with those determined by N.M.R (Gonano et al, 1967).…”

“…These values are smaller than the theoretical ground state 6 S 5/2 saturated magnetic moment (5 μ B ). The observed reduction of the moments is explained by covalent bonding for YIG Fuess et al, 1976) or topological frustration for FeF 3 (Ferey et al, 1986). When the proposed values (Guillot., et al 1983) are chosen in the refinement of the neutron diagrams at 453, 400 and 283 K, we observe that the calculated intensities of the reflections (211) and (220) which have a high magnetic contribution are lower than the observed intensities.…”

Interfacial and Bulk Magnetic Properties of Stoichiometric Cerium Doped Terbium Iron Garnet Polycrystalline Thin Films

“…It is worth noting that the iron sublattice magnetization (in tetrahedral and octahedral sites) from neutron scattering refinement is about 3.65–3.80 μ B (at 300 K) and 4.26 μ B (at 117 K), which only exhibits negligible temperature dependence as opposed to the rare‐earth sublattice. [ 45,46 ] Furthermore, this increase in coercive field does not approach infinity if the rare‐earth sublattice is unsaturated. [ 47 ] Above compensation temperature, the coercivity decreases as it scales inversely with effective saturation magnetization.…”

Covalency Effects in Magnetic Interactions

“…[70]) it was shown that conventional profile analysis using a medium flux reactor was as satisfactory a means of determining the magnetic moment as the use of polarization analysis [71] to separate the magnetic and nuclear scattering using a high-flux reactor. Except for NiO 1641 discussed above and Tb,Fe,O,, [72] where the Y,Fe,O,, form factors for octahedrally and tetrahedrally coordinated Fe3 + determined [73] by polarised neutrons were used, these powder studies have used free ion form factors to estimate moment reductions. It should be added that although profile analysis can handle successfully quite complicated nuclear unit cells it is essential that the magnetic moments be determined as accurately as possible because of the fact that the covalency parameters are given by the quite small difference between the expected and observed magnetic moments.…”