Influence of Co content on structural and magnetic properties of Sr 0·68 La 0·32 Fe 11·7 Zn 0·30 − x Co x O 19 M type hexaferrites.

Hexagonal ferrite Sr0·68La0·32Fe11·7Zn0·30 − xCoxO19(0 ≤ x ≤ 0·30) magnetic powders and magnets have been synthesised by a ceramic process. The phase compositions of the calcined powders were analysed using X-ray diffraction. All the X-ray diffraction peaks belong to the single hexagonal ferrite. The micrographs of the magnets were characterised using a field emission scanning electron microscopy. The hexagonal ferrite magnets have formed the plate-like hexagonal structure. Magnetic properties of the magnets were measured at room temperature using a permanent magnetic measure equipment. The remanence and maximum energy product of the magnets first increase tillx = 0·10 and then decrease with increasingxfrom 0·10 to 0·30. However, the intrinsic coercivity and magnetic induction coercivity of the magnets increase with the increase ofxfrom 0 to 0·30. The ratio ofHk/Hcjdecreases gradually with the increase ofxfrom 0 to 0·30. [ABSTRACT FROM AUTHOR]