Canted ferrimagnetism in Ca super(2+)Sc super(3+) substituted yttrium-iron-garnet

The temperature dependence of the magnetization of Y sub(3-y-z)Ca sub(y)Lu sub(z)Fe sub(5-x)Sc sub(x)O sub(12) (0.6 less than or equal to x less than or equal to 1.2, 0 less than or equal to y less than or equal to 0.3, 0 less than or equal to z less than or equal to 0.9) epitaxial garnet films was measured from 4.2 K up to the Curie temperature. For x = 0.7 and T greater than or equal to 50 K, 4 pi M sub(s) is enhanced by about 10% compared to the magnetization of Sc sub(0.7) YIG. At T < 50 K, a reduction of the magnetization, increasing with increasing substitution, was observed for all the measured samples. Agreement between the experimental results and molecular field models was obtained by taking into account the canting of the unsubstituted sublattice, the presence of charge compensating Fe super(4+) ions, a low-temperature ordering of Fe super(3+) ions with less than two magnetic nearest neighbors, and assuming a lattice parameter-dependent exchange interaction ratio with d(J sub(dd)/J sub(ad))/da = 28 nm.