Influence of Co content on structural and magnetic properties of Sr_0·68La_0·32Fe_11·7Zn_{0·30 − x}Co_xO₁₉ M type hexaferrites

Abstract

Hexagonal ferrite Sr_0·68La_0·32Fe_11·7Zn_{0·30 − x}Co_xO₁₉ (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 till x = 0·10 and then decrease with increasing x from 0·10 to 0·30. However, the intrinsic coercivity and magnetic induction coercivity of the magnets increase with the increase of x from 0 to 0·30. The ratio of H_k/H_cj decreases gradually with the increase of x from 0 to 0·30.

Keywords:

• Hexagonal ferrites
• La–ZnCo substitution
• Magnetic properties
• X-ray diffraction

Acknowledgement

We acknowledge the financial support from the Joint Funds for Fostering Talents in Henan Province of National Natural Science Foundation of China [grant number U1404515].