Study of Structural, Electrical and Magnetic properties of Nd-Ti co-doped BiFeO_3 Nanoparticles
Single-phase BFO nanoparticles with compositions Bi 0.9 Nd 0.1 FeO 3 and Bi 0.9 Nd 0.1 Fe 0.95 Ti 0.05 O 3 have been synthesized by low temperature citric acid assisted auto-combustion route. Thereafter, effect of the co-substitutions on structural, electrical and magnetic properties of BFO has been investigated. X-ray diffraction revealed partial phase transformation from rhombohedral to orthorhombic for 10% Nd-substituted BFO whereas Nd-Ti sample showed traces of pseudo-tetragonal symmetry. TEM micrographs confirmed nearly uniformly shaped particles with particle size under 50 nm. Resistivity of the co-doped sample increased remarkably and found to be ρ dc = 1.85×10 11 Ω-cm. Thus, Ti 4+ ion reduced leakage current by suppressing oxygen vacancies. Ferroelectric nature has been improved on account of structural distortion induced by Nd-Ti ions as well as decreased leakage current. Also, dielectric behaviour improved significantly on doping. A broad peak nearby T N in temperature-dependent dielectric confirmed magnetoelectric coupling for all the samples. The wasp-waisted type M -H loop was observed with improved weak ferromagnetism due to structural distortion induced by dopant ions and super-exchange like interaction between dopants and host ions. Therefore, co-doping of Nd and Ti ions considerably has enriched the electric and magnetic properties of BFO nanoparticles.
