Flexible and self-standing polyvinylidene fluoride (PVDF) films loaded with nanofillers, reduced graphene oxide (RGO), zinc oxide (ZnO) and magnetic iron oxide (Fe3O4) nanoparticles, were prepared by a solvent casting method.

Flexible inorganic-organic magneto-electric (ME) nanocomposite films (PVDF, PVDF-GO, PVDF-Fe3O4 and PVDF-GO-Fe3O4), composed of well-dispersed graphene oxide (GO 5 wt%) and magnetic Fe3O4 nanoparticles (5 wt%) embedded into a poly(vinylidene-fluoride) (PVDF) matrix, have been prepared by a solvent casting route. The magnetic, ferroelectric, dielectric, magneto-dielectric (MD) coupling and structural properties of these films have been systematically investigated. Magnetic (Ms = 2.21 emu g(-1)) and ferroelectric (P = 0.065 μC cm(-2)) composite films of PVDF-GO-Fe3O4 (PVDF loaded with 5% GO and 5% Fe3O4) with an MD coupling of 0.02% at room temperature (RT) showed a three times higher dielectric constant than that of the pure PVDF film, with a dielectric loss as low as 0.6. However, the PVDF-Fe3O4 film, which exhibited improved magnetic (Ms = 2.5 emu g(-1)) and MD coupling (0.04%) properties at RT with a lower dielectric loss (0.3), exhibited decreased ferroelectric properties (P = 0.06 μC cm(-2)) and dielectric constant compared to the PVDF-GO-Fe3O4 film. MD coupling measurements carried out as a function of temperature on the multi-functional PVDF-GO-Fe3O4 film showed a systematic increase in MD values up to 100 K and a decrease thereafter. The observed magnetic, ferroelectric, dielectric, MD coupling and structural properties of the nanocomposite films are attributed to the homogeneous dispersion and good alignment of Fe3O4 nanoparticles and GO in the PVDF matrix along with a partial conversion of nonpolar α-phase PVDF to polar β-phase. The above multi-functionality of the composite films of PVDF-Fe3O4 and PVDF-GO-Fe3O4 paves the way for their application in smart multiferroic devices.

The radiation-resistant response of BaTiO 3 in the tetragonal and rhombohedral phases on exposure to 100 MeV Ag 7+ ion irradiation was investigated by in situ X-ray diffraction (XRD) at room temperature (300 K) and low temperature (25 K), respectively. This study revealed that the BaTiO 3 in rhombohedral phase retained crystallinity up to an ion fluence of 1910 14 ions/cm 2 , whereas tetragonal phase amorphized at much lower fluence viz. 1910 13 ions/cm 2 . The in situ XRD along with Raman spectroscopy studies revealed that BaTiO 3 in rhombohedral phase is more radiation resistant than that of tetragonal phase. The density functional theory (DFT) calculations confirmed higher bond strength of rhombohedral phase as compared to tetragonal phase, which supported the experimental result of higher radiation stability of rhombohedral phase. The theoretical predictions on high-temperature phase will be of relevance to the nuclear waste applications. orthorhombic (Amm2)?rhombohedral (R3m), in between 400 and 160 K. The high-temperature cubic phase is paraelectric and all the remaining phases are ferroelectric. These structural phase changes are originated due to internal distortions induced stretching of paraelectric cubic lattice along different crystallographic directions, along an edge (<001> in tetragonal), along a face diagonal (<011> in orthorhombic), and along a body diagonal (<111> in rhombohedral). 5,6 On exposure to the energetic heavy ion, properties of the materials are altered by introducing defects, changing structures including amorphization or loss of crystallinity. This type of ion irradiation offers exclusive way of creating extreme surroundings like in nuclear environment, and therefore, the ion irradiation studies of the ABO 3 structures in different phases are of interest because perovskite titanates have potential application for immobilization of fission products and actinides from nuclear waste.