The enhanced of magnetic and electrical properties of Bi5FeTi3O15 compound with replacing Co for Ti sites

•Four-layered Aurivillius Bi5FeTi3-xCoxO15 (x = 0.0, 0.1, 0.3, 0.5, 0.6 and 0.7) compounds were fabricated by sol–gel method.•The multiferroic properties of Bi5FeTi3-xCoxO15 compounds confirm with simultaneous presence of M−H and P-E loops.•By substituting Ti sites by Co ion the magnetic behaviour of BFT changes from antiferromagnetic to ferromagnetic feature.•The dielectric properties of Bi5FeTi3-xCoxO15 were measured in the frequency ranging from 100 Hz to 10 MHz. In this work, four-layered Aurivillius Bi5FeTi3-xCoxO15 (x = 0.0, 0.1, 0.3, 0.5, 0.6 and 0.7) compounds were fabricated by sol–gel method, in order to investigate the effect of Co substitution for Ti on the magnetic and electrical properties of Bi5FeTi3O15 (BFT). The phase formation and crystal structure of these compounds were investigated by using X-ray diffraction (XRD) and Rietveld refinement. The plate-like grain structure of particles were confirmed by field emission scanning electron microscope (FE-SEM). The mean thickness of Bi5FeTi3-xCoxO15 layers increase with increasing Co substitution. The multiferroic characterization of these samples were confirmed by the M−H and P-E hysteresis loops at room temperature. By substituting Ti sites by Co ion the magnetic behaviour of BFT changes from antiferromagnetic to ferromagnetic. The highest remanent magnetization value at room temperature is 0.67 emu/g that occurs in the cobalt substituted sample with x = 0.6. Simultaneously enhancing of magnetic and electrical properties in studied samples can allow us that use those for practical applications.