Anisotropy of Gadolinium Iron Garnet

Abstract

The ``one-ion'' theory of origin of anisotropy has been tested by comparing the calculated value of the gadolinium contribution to the anisotropy of GdIG at 0°K with experimental measurements. Crystal field, dipolar, and dipole—crystal field effects are included in the calculation. The median of the values obtained using the crystal field parameters for Gd3+ in four diamagnetic garnets agrees within 3% with the result of torque measurements on a pure GdIG crystal. The experimental value, −21.9×104 ergs/cc, is approximately 10% lower than previous values for the anisotropy of GdIG. The good agreement between the calculated and experimental anisotropies provides quantitative confirmation of the theory used in the calculations.

First-principles study of magnon-phonon interactions in gadolinium iron garnet

“…230 Ia3d. 6,7 The cubic cell contains eight formula units, as shown in Fig. 1, where rare-earth gadolinium ions occupy the 24c Wyckoff sites (green dodecahedrals), the Fe O and Fe T occupy the 16a sites (blue octahedrals) and 24d sites (yellow tetrahedrals), respectively, and the O ions occupy the 96h sites (red balls).…”

“…1, where rare-earth gadolinium ions occupy the 24c Wyckoff sites (green dodecahedrals), the Fe O and Fe T occupy the 16a sites (blue octahedrals) and 24d sites (yellow tetrahedrals), respectively, and the O ions occupy the 96h sites (red balls). The atomic sites from the experimental structural parameters (TABLE I) [6][7][8] are used in the study. To calculate the electronic structure and total energy of GdIG, we use DFT, as implemented in the Vienna ab initio simulation package (VASP).…”

Magnetic and structural properties of single-phase Gd3+-substituted Co–Mg ferrite nanoparticles

“…63 Although Gd 3+ has zero orbital angular momentum, gadolinium has been reported to contribute to and strengthen anisotropy. 64 The coercivity of the sample increased from 1702.28 Oe at 300 K to 11 959.53 Oe at 10 K. The enhanced coercivity is attributed to the reduced thermal uctuation energy at 10 K, which is less effective in reducing the effects of magnetocrystalline anisotropy energy. In addition, the enhanced coercivity could be interpreted as a result of the energy barriers in the nanoparticles becoming more apparent at low temperature.…”

New Nanosized (Gd3+, Sm3+) Co-doped Zinc Ferrite for Telecommunication Applications. Magnetic and Structural Properties.

“…Indeed, doping with small amounts of rare earth (RE) elements can improve the magnetic properties, especially the T B of nanoferrites. Although a Gd 3+ ion has a zero orbital angular momentum, it has been reported in the literature that Gd contributes to and enhances the anisotropy [64].…”