Effect of Ho3+ substitutions on the structural and magnetic properties of BaFe12O19 hexaferrites

Holmium doped barium based hexaferrites BaFe12-2xHo2xO19 with (x = 0.0-1.0) were synthesized by solid state reaction method. Structural and magnetic characterization of these ferrites provide significant information about their reactive physical properties. X-ray analysis reveals that in all samples M-type structure exist with few secondary phases. Scanning electron microscope revealed the grain size of the specimen. The results show that grain size decreases with the substitution degree of Holmium. Thus rare earth element Holmium Ho3+ acts as a grain growth inhibitor. The magnetic hysteresis loops show the variation in the values of magnetic parameters like saturation magnetization (M-s), remanent magnetization (M-r) and coercivity (H-c) were observed by changing Ho3+ content in BaFe12-2xHo2xO19 ferrites. Coercivity showed a maximum value of 2230 Oe for (x = 0.4) and then decreasing trend were observed in the values of H-c, Mr and Ms with the increasing substitution degree of rare earth element Holmium. (C) 2010 Elsevier B.V. All rights reserved.