MAGNETIC-PROPERTIES OF BA2ME2FE28O46 (ME2-X, ME = NI, CU, MG, AND ZN) HEXAFERRITES

Polycrystalline samples of Ba2Me2Fe28O46 (Me2-X, Me = Ni, Cu, Mg, and Zn) hexagonal ferrite have been prepared by the classical ceramic method. Low-temperature magnetic properties and Curie temperature were investigated. The substitution of Fe2+ ion with Ni2+, Cu2+, and Mg2+ ions decreases spontaneous moment of Me2-X due to the preference of these ions for the octahedral sites of spinel S blocks. The substitution of Fe2+ ions with Zn2+ ions increases spontaneous moment due to the preference of Zn2+ ions for the tetrahedral sites. Lower Curie temperatures of Zn2-X, Cu2-X and Mg2-X compounds originate from the much small magnetic moment of these ions. Ni2+ ion has a magnetic moment smaller than Fe2+ ion, while Ni2-X compound has a Curie temperature as high as Fe2-X. It may be due to different space distribution of 3d electrons of Ni from Fe.