• Khan, M. N. I.
• Hossain, M. N.
• Rhaman, M. M.
• Islam, M. F.
• Matin, M. A.
• Hakim, M. A.

Abstract

Pure and co-doped multiferroic bismuth ferrite (BFO) nanoparticles were synthesized by the sol-gel method. Samarium and cobalt were used as co-dopants in BFO. The co-doped composites had the formula Bi<SUB>1-x</SUB>Sm<SUB>x</SUB>Fe<SUB>1-y</SUB>Co<SUB>y</SUB>O<SUB>3</SUB>, where x = 0.1 and y = 0.05, 0.1, or 0.15. Rietveld refinement of X-ray diffraction patterns showed a well-arranged crystalline rhombohedral structure with space group R3c. The rhombohedral structure transformed to an orthorhombic structure with space group Pbam in co-doped BFO nanoparticles. The ferromagnetic properties of synthesized nanoparticles were investigated in detail. Bi<SUB>0.9</SUB>Sm<SUB>0.1</SUB>Fe<SUB>0.85</SUB>Co<SUB>0.15</SUB>O<SUB>3</SUB> showed a large increase in saturation magnetization and remanent magnetization to 3.2 and 1.5 emu/g, respectively. The large increase in magnetization with a reasonable squareness ratio and coercive field of co-doped BFO nanoparticles means they have potential uses in memory and spintronic devices. Electric properties such as resistance, reactance, AC resistivity, and AC conductivity were analyzed as a function of frequency. The AC resistivity decreased and the AC conductivity increased greatly with increasing co-dopant concentration. The ferroelectric behavior of pure and co-doped samples was also investigated. The maximum polarization and remanent polarization greatly increased to 12.5 and 7.5 μC/cm<SUP>2</SUP>, respectively, in Bi<SUB>0.9</SUB>Sm<SUB>0.1</SUB>Fe<SUB>0.85</SUB>Co<SUB>0.15</SUB>O<SUB>3</SUB>. The increased conductivity and reduced resistivity of co-doped samples may also be useful in efficient photovoltaic solar cells....

Topics

• nanoparticle
• resistivity
• x-ray diffraction
• composite
• cobalt
• magnetization
• saturation magnetization
• space group
• Bismuth
• Samarium