Advanced Functional Materials, Vol.24, No.8, 1067-1073, 2014
Multiferroic Polymer Laminate Composites Exhibiting High Magnetoelectric Response Induced by Hydrogen-Bonding Interactions
The coupling of the magnetic, electric, and elastic properties in multiferroics creates new collective phenomena and enables next-generation device paradigms. In this work, the hydrogen bonding interaction between hydrate salts and ferroelectric polymers is exploited in the development of high-performance magnetoelectric (ME) polymer laminate composites. The microstructures and crystallite structures of the Al(NO3)(3)center dot 9H(2)O doped poly(vinylidene fluoride-co-hexafluoropropylene), P(VDF-HFP), are carefully studied. The effect of hydrogen bonding interaction on the polarization ordering of the ferroelectric polymers is investigated by 2D wide-angle X-ray diffraction, polarized Fourier transform infrared spectra, and dielectric spectra at varied frequencies and temperatures. It is found that hydrogen bond not only promotes the formation of the polar crystallite phase but also improves the polarization ordering in the ferroelectric polymer, which subsequently increases the remnant polarization of the polymers as verified in the polarization-electric field loop measurements. These entail marked improvement in the ME voltage coefficients (((ME) over bar)) of the resulting polymer laminate composites based on ferromagnetic Metglas relative to analogous composites. The composite exhibits a state-of-the-art ((ME) over bar) value of 20 V cm(-1) Oe under a dc magnetic field of approximate to 4 Oe and a colossal ((ME) over bar) of 320 V cm(-1) Oe at a frequency of 68 kHz.