  Multiferroic CoFe2O4-Ba0.95Ca0.05Ti0.89Sn0.11O3 core-shell nanofibers
(CFO@BCTSn NFs) were synthesized by a sol-gel co-axial electrospinning
technique. The scanning electron microscope and transmission electron
microscope were used to check nanofibers' core-shell structure/configuration.
X-ray diffraction and a high-resolution transmission electron microscope were
used to confirm the spinel structure of CFO and the perovskite structure of
BCTSn. The magnetic character of the resultant CFO@BCTSn NFs was determined by
SQUID magnetometry. The piezoelectricity was verified using piezo-response
force microscopy, which revealed an entirely covered ferroelectric shell
outline, in accordance with SEM and TEM observations. The magnetoelectric (ME)
coefficient was measured as a function of the applied external DC magnetic
field. The maximum ME coefficient obtained for the CFO@BCTSn NFs was 346 mV
cm-1 Oe-1. The high magnetoelectric coupling suggests that CFO@BCTSn NFs could
be a promising candidate for magnetic field sensor and magnetoelectric device
applications.
