Structural and magnetic properties of BaFe/sub 12-2x/Co/sub x/Ti/sub x/O/sub 19/ powders prepared by the glass crystallization method

Abstract

The glass crystallization method is shown to be suitable for preparing BaFe/sub 12-2x/Co/sub x/Ti/sub x/O/sub 19/ powders with a nearly perfect crystallographic structure and a narrow particle size distribution. The dependences of the specific magnetization, the coercivity, and the particle size distribution on both the annealing temperature and the Co-Ti content correlate in a characteristic way. Furthermore, the lattice parameters, the specific surfaces and the thickness of the effective nonmagnetic surface layer were determined. The coercivity of the hexaferrite magnetic tapes is more than 8*10/sup 3/ A/m higher than for the corresponding powders.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>