Effect of Dy+3 on the structure and static magnetic properties of spin-glass MnZn ferrite nanoparticles

Structural and static magnetic properties of a series of ferrites nanoparticles (the size ranges from 7.6 to 13.5 nm) having nominal chemical composition DyxMn0.5Zn0.5Fe2-xO4 (x 0, 0.02, 0.04, 0.06) have been investigated. The x-ray diffraction analysis clarifies that the samples crystallize in typical cubic spinel structure. Incorporation of Dy ions in the Mn0.5Zn0.5Fe2O4 lattice structure has been proved by Raman spectroscopy measurements. Correspondingly, a significant increase in the grain size and a dramatic change in the magnetic properties are observed. The magnetization versus magnetic field M(H) plots are nonhysteretic where the coercivity remains zero and display Langevin-like behavior. The temperature dependence of magnetization M(T) plots in field cooling regime shows spin-glass behavior indicating a strong interaction between the magnetic moments. The blocking temperature determined from M(T) plots in zero field cooling regime increases as the Dy content increases. (C) 2013 American Institute of Physics.