Nanoscale magnetoelectric coupling in multiferroic BiFeO3 nanowires

Nanoscale magnetoelectric (ME) coupling has been observed in multiferroic BiFeO3 (BFO) nanowires (NWs) synthesized by sol-gel based electrospinning technique. Under externally imposed electric fields these NWs exhibit the systematic evolution of a magnetic domain pattern as established by magnetic force microscopy (MFM), confirming the presence of ME coupling. Interestingly, the effect persists even after the electric field is removed, thereby implying an electric-field-induced magnetic hysteresis phenomenon in BFO NWs. The estimated ME coupling coefficient from tip-sample interactions is alpha(33) = 2.2 x 10(-10) sm(-1), and the equivalent ME voltage coefficient is 0.49 V cm(-1) Oe(-1). The obtained values of the ME coupling coefficient are higher than the reported values for BFO bulk and thin films. These results promise one-dimensional (1D) multiferroic BFO NWs as potential candidate for manipulating magnetism through electric field at the nanoscale and provide great opportunities towards magnetoelectrically tunable multiferroic devices. (C) 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim