Effect of Dy3+ substitution on structural, magnetic and dielectric properties of BiFeO3-PbTiO3multiferroics

Multiferroic $0.6\text{Bi}_{(1-\mathrm{x})}\text{Dy}_{\mathrm{x}}\text{FeO}_{3}-0.4\text{PbTiO}_{3}\ (\mathrm{x}=0$, 0.10) nanoparticles were synthesized via sol-gel route. The effect of rare earth $\text{Dy}^{3+}$ ion substitution on structural, magnetic and dielectric properties of $\text{BiFeO}_{3}-\text{PbTiO}_{3}$ system has been studied. Rietveld refinement studies of X-ray diffraction profiles reveal that system exhibit cubic $(\text{Pm}\bar{3}\mathrm{m})$ and tetragonal (P4mm) crystal structure for x = 0 and single cubic (Pm3m) phase for x = 0.10. Experimental results show that $\text{Dy}^{3+}$ doping suppresses the modulated spin cycloid of BiFeO3 results in net remnant magnetization. Dielectric studies show that the conductivity of the sample decreases with $\text{Dy}^{3+}$ ion substitution in the composition, which indicates that $\text{Dy}^{3+}$ doping suppresses the oxygen vacancies.