Pr and Cr co-doped BiFeO₃ nanotubes: an advance multiferroic oxide material

Department of Material Sciences, S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake City, Kolkata - 700 098, India

Abstract

Arrays of single phase pure and Pr-Cr co-doped BiFeO₃ (BFO) nanotubes (NTs) with compositions BiFeO₃ and Bi_0.9Pr_0.1Fe_0.9Cr_0.1O₃ have been synthesized using Anodic Aluminium Oxide (AAO) template (pore diameter ~250 nm) by wet chemical liquid phase deposition technique. All the NTs show ferromagnetic nature at room temperature (RT). Better magnetic properties are observed in the co-doped BFO NTs with the value of saturation magnetization (M_S) ~49 memu/g, magnetization at the remanence (M_R) ~12 memu/g and coercive field (H_C) ~103 Oe. Increase of ferromagnetic signature in the co-doped BFO NTs is believed to be due to the collapse of the space-modulated spin structure. Significant increase in the dielectric characteristics in co-doped BFO NTs suggests lowering of leakage current due to the reduction of the oxygen vacancies in the structure. Strong Magnetodielectric effect (MD), expressed by [ε_r(H)-ε_r(0)]/ε_r(0) is observed in doped BFO NTs, where the increase of the dielectric constant is noticeable with the increase in the applied magnetic field. The codoped BFO NTs show noticeable increase in MD effect at a lower field (1-2 kOe).