Multiferroic CoFe₂O₄-Ba_0.95Ca_0.05Ti_{0 .89}Sn_0.11O₃ Core-Shell Nanofibers for Magnetic Field Sensor Applications

Multiferroic materials with coexisting of at least twoferroicorders (ferromagnetic, ferroelectric, or ferroelastic) have recentlyattracted the interest of researchers due to their potential applicationsas multifunctional devices. Herein, we report the synthesis and detailedcharacterization of the multiferroic CoFe2O4-Ba0.95Ca0.05Ti0.89Sn0.11O3 core-shell nanofibers (CFO@BCTSn NFs)prepared by a sol-gel coaxial electrospinning technique. Thescanning and transmission electron microscopes were used to checknanofibers' core-shell structure/configuration, withfiber diameters ranging from 150 to 250 nm. The X-ray diffractionanalysis confirms the presence of both the spinel structure of theCFO and the perovskite structure of the BCTSn. Piezoresponse forcemicroscopy and magnetic hysteresis were used to confirm the multiferroicityof CFO@BCTSn NFs. Notably, the maximum magnetization and remanentmagnetization of NFs are found to be 11.63 emu g(-1) and 1.43 emu g(-1), respectively. Meanwhile, themaximum piezoelectric response d (33) (eff) is around 6 pm V-1. The magnetoelectric(ME) coefficient obtained for the CFO@BCTSn NFs is 346 mV cm(-1) Oe(-1) at the field of 10 kG. These findings maylead to development of nanoscale Pb-free magnetic field sensors andmagnetoelectric device applications.