Ni-Zn-Cu-ferrite-PVDF multiphase nanocomposite material for the application of multiferroics and improved EMI shielding effectiveness

In search of an effective multifunctional laminated nanocomposite material useful for microwave absorption and multiferroic applications, the nanoparticles of Ni-Zn-Cu-ferrite (NZCF) were successfully encapsulated inside the matrix of poly(vinylidene fluoride) (PVDF). The crystallographic phases of bare NZCF, PVDF and NZCF-PVDF nanocomposite films were confirmed by X-ray diffraction measurement. Field emission scanning electron microscopy (FESEM) of NZCF-PVDF nanocomposite films reveals the presence of PVDF matrix all around the surface of the NZCF nanoparticles. The static magnetic properties were measured for both bare NZCF and NZCF-PVDF and different magnetic information were extracted from the study of magnetic measurement. The substantial magnetic responses with comparatively large magnetizations of 2.64 and 13.52 emu/g for S1P20 and S2P20 nanocomposite films respectively have been obtained. Dielectric response study of NZCF-PVDF nanocomposite films was estimated as a function of frequency and temperature. Also, the enhancement of the dielectric constant as a function of temperature with a proper signature of ferroelectric to paraelectric transition was observed for NZCF-PVDF nanocomposite films. This high dielectric constant of NZCF-PVDF is found due to the formation of NZCF-PVDF interfaces inside the resultant nanocomposite films. Ferroelectric hysteresis loops of NZCF-PVDF nanocomposite films were observed at 100 Hz which confirms the presence of ferroelectric ordering of the resultant nanocomposite films. Magneto-dielectric (MD) coefficient of NZCF-PVDF nanocomposite films is observed at room temperature and it confirms the presence of significant interactions between the magnetic and ferroelectric order parameters at the interfaces inside the nanocomposite materials. Magneto-dielectric (MD) coefficient of NZCF-PVDF nanocomposite films is observed at room temperature with a maximum MD (%) variation of S1P20 is 30.08 at frequency 1 MHz for an external magnetic field of 1000 Oe. It also suggests the onset of multiferroic property of NZCF-PVDF nanocomposite films. Shielding effectiveness study of NZCF-PVDF nanocomposite films was conducted within the frequency range of 8–18 GHz and a very high value of total shielding effectiveness with large contribution of microwave absorption loss was found. Shielding effectiveness study of NZCF-PVDF nanocomposite films was conducted within the frequency range of 8–18 GHz and a very high value of total shielding effectiveness (SET) ∼ -79 dB at ∼ 12.64 GHz for S2P10 nanocomposite film with large contribution of microwave absorption loss (SEA) ∼ -51 dB at ∼ 12.64 GHz was found. These novel properties of unique NZCF-PVDF nanocomposite films are very much interesting for the applications in high frequency magneto-dielectric device applications.