Enhanced multiferroic properties in Ti-doped Bi2Fe4O9 ceramics

Structural, magnetic, and ferroelectric properties have been investigated for Bi(2)Fe(4(1-x))Ti(4)xO(9) (0 <= x <= 0.2) bulk ceramics, which were synthesized by a modified Pechini method. X-ray diffraction reveals that all samples are single phase with no impurities detected. Compared with antiferromagnetic Bi2Fe4O9 compound, doping with Ti ions induces the appearance of weak ferromagnetism at room temperature, which is discussed in terms of the collapse of the frustrated antiferromagnetic spin structure. Moreover, appropriate Ti doping also significantly reduces electric leakage and leads to the enhancement of electrical polarization. Among all samples, the optimal multiferroics with M-r similar to 0.0188 emu/g and P-r similar to 0.262 C/cm(2) at room temperature is found for x=0.15 ceramics. It is thus shown that Ti-doped Bi2Fe4O9 is a promising candidate for preparing multiferroic materials. (C) 2010 American Institute of Physics. [doi:10.1063/1.3478705]