Magnetic and magnetostrictive behavior of Dy3+ doped CoFe2O4 single crystals grown by flux method

We studied the effect of Dy³⁺ content on the magnetic properties of cobalt ferrite single crystal. The single crystals of CoFe_1.9Dy_0.1O₄ were grown by the flux method using Na₂B₄O₇.10 H₂O (Borax) as a solvent (flux). The black and shiny single crystals were obtained as a product. The X-ray diffraction analysis at room temperature confirmed the spinel cubic structure with lattice constant a=8.42 Å of the single crystals. The compositional analysis endorses the presence of constituents Co, Fe and Dy elements after sintering at 1300 °C within the final structure. The magnetic hysteresis measurements at various temperatures viz. 10 K, 100 K, 200 K and 300 K reveal the soft ferrimagnetic nature of the single crystal than that of for pure CoFe₂O₄. The observed saturation magnetization (M_s) and coercivity (H_c) are found to be lower than that of pure CoFe₂O₄ single crystal. The magnetostriction (λ) measurement was carried out along the [001] direction. The magnetic measurements lead to conclude that the present single crystals can be used for magneto-optic recording media.