“…63 emu/g). Unlike the replacement of transition metal elements Cu, Mn, Ni for Fe 2+ into octahedral B-site [24, 25,27], preferably the replacement of 𝑍n 2+ ions for Fe 3+ at tetrahedron A-site occurs [19,26], simultaneously 𝐹𝑒 2+ amount at the octahedral B-site gives electrons to become Fe 3+ in order to balance the charge of cell network [19,26]. Since the ionic radius of the Fe 3+ ion is 0.64 Å and the ionic radius of the Zn 2+ ion is 0.74 Å, the substitution of Zn with content x = 0.10 caused a slight increasing of the lattice constant (a = 8.386 A 0 ) in comparison with Fe 3 O 4 (a = 8.3760 A 0 ) [30,36].…”