Magnetic Properties of Mn1-xZnxFe2O4 (0 <= x <= 1) Nanoparticles Fabricated by a Template-assisted Sol-gel Method

A series of Mn-Zn ferrite nanoparticles with a nominal composition Mn1-xZnxFe2O4 (0 <= x <= 1 with steps of 0.2) were synthesized by a template-assisted sol-gel method. The phase identification and magnetic properties of Mn1-xZnxFe2O4 were measured by XRD and VSM. The effects of Zn content on the structure and magnetic properties of Mn1-xZnxFe2O4 were studied. It is found that all the Mn1-xZnxFe2O4 samples with different Zn contents exhibit cubic spinel structure in single phase. With the increase of Zn content, the values of the crystal plane spacing d, average crystal size D, saturation magnetization M-s, Curie temperature T o all exhibit a decreasing trend, while, the coercivity H-c shows a first increasing then decreasing trend. For the Mn0.6Zn0.4Fe2O4 samples, the coercivity H-c is the maximum. The decreasing of M-s is attributed to the Yafet-Kittel canting, the decreasing of T-c is due to the decreasing of anti-ferromagnetic coupling among sublattices. The variation trend of the coercivity H-c can be explained on the basis of the changes of magneto-crystalline anisotropy K-1 of the samples caused by the change of Mn1-xZnxFe2O4 formula with different Zn contents x.