Structural and magnetic properties of barium hexaferrites with Gd-Co substitution

A first examination concerning possible replacement of La by Gd in Ba-La-Co hexaferrites has been conducted. Substituted samples according to the formula Ba1-xGdxFe12-xCo0.1O19 (x=0.0, 0.1, 0.2, 0.3, 0.4) were prepared by classical ceramic route. A La-Co substituted sample with composition Ba0.8La0.2Fe11.8Co0.2O19, (X=0.2) was also prepared for comparison. The structural and magnetic characteristics have been studied by XRD, VSM, SEM and EDX techniques. The substituted samples contain small amount of alpha-Fe2O3 impurities and traces of CoFe2O4, Fe2GdO4 and GdFeO3. The coercivity of samples with x= 0.1-0.2 is higher up to 15% than in BaFe12O19, while the saturation magnetization and remanence values are lower. The Ba0.9Gd0.1Fe11.9Co0.1O19 sample (x = 0.1) presents similar values of H-c and sigma(r) to the La-Co (x = 0.2) sample Ba0.8La0.2Fe11.8Co0.2O19, demonstrating the potential for use of Gd in rare-earth substituted hexaferrite permanent magnet materials. (c) 2006 Elsevier B.V. All rights reserved.