Substrate clamping effect onto magnetoelectric coupling in multiferroic BaTiO3-CoFe2O4 core-shell nanofibers via coaxial electrospinning
MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Science, and Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, and State Key Laboratory for Manufacturing System Engineering, Xi'an Jiaotong University 710049, Xi'an, PRC
Received: 20 September 2015
Accepted: 16 October 2015
We report large lateral magnetoelectric (ME) coupling coefficients α31 of and in substrate bonded and free-standing multiferroic BaTiO3-CoFe2O4 (BTO-CFO) core-shell nanofibers (NFs) with and without substrate clamping effect, respectively. The BTO-CFO core-shell NFs were synthesised by a sol-gel coaxial electrospinning technique, and their ME coupling was directly observed by demonstrating the evolution of piezoelectric coefficient (d33), ferroelectric domain, and phase contrast induced by an external magnetic field. These impressed α31 coefficients originated from the nanoconfinement of the interphase elastic interaction between the ferromagnetic core fiber and the ferroelectric shell interlayer, as well as the strain transformation at the one-dimensional (1D) fiber boundary. This means that the decreasing substrate clamping effect results in an enhanced ME coupling in multiferroic NFs, which is similar to that of thin films. These findings make people understand the substrate clamping effect and enable nanoscale ME device applications.
PACS: 75.85.+t – Magnetoelectric effects, multiferroics / 77.65.Bn – Piezoelectric and electrostrictive constants / 77.80.bn – Strain and interface effects
© EPLA, 2015