Samarium Substitutions in Yttrium Iron Garnet

Polycrystalline garnets of the form (3 − x)Y2O3·xSm2O3·5Fe2O3 have been prepared where x was varied from 0 to 3 in six steps. Lattice constants were found to vary linearly from 12.374±0.005 A for yttrium irongarnet (x = 0) to 12.533±0.005 A for samarium iron garnet (x = 3). The theoretical x-ray densities were calculated and vary from 5.17 gms/cc for x = 0 to 6.22 gms/cc for x = 3. Magnetic moments were measured from 77° to 600°K. No magnetic compensation points were observed. The Curie temperature for these garnets is 570±10°K. Thermal magnetization curves for this series indicate that samarium substitution for yttrium produces very little change in the magnetization. The relative complex initial permeability was measured from dc to 2 kMc for several temperatures. The results of these measurements are discussed briefly.