Investigations on electrical and magnetic properties of multiferroic [(1−x)Pb(Fe0.5Nb0.5)O3−xNi0.65Zn0.35Fe2O4] composites

Abstract

Here, we report the magnetic, ferroelectric, dielectric properties, and Raman spectroscopic studies of multiferroic [(1−x)Pb(Fe0.5Nb0.5)O3−xNi0.65Zn0.35Fe2O4] composites at room temperature. The phase formation of composites was confirmed independently from the X-ray diffraction and Raman studies. The room temperature magnetic studies reveal ferromagnetic like behavior of these composites in contrast to the paramagnetic nature of Pb(Fe0.5Nb0.5)O3. Furthermore, with increasing x, the saturation magnetization, remnant magnetization, and coercive fields are found to increase. The electrical characterizations of these composites reveal a decrease in remnant polarization and dielectric constant with increasing x. More importantly, the x = 0.2 composite is found to be a very good multiferroic material at room temperature among the composites and could be a potential candidate for future potential applications.

Exploring the Magnetoelectric Coupling at the Composite Interfaces of FE/FM/FE Heterostructures

“…The ferroelectric transition temperature is found to shift towards higher temperature compared to the ferroelectric transition of pure PFN thin film (~ 400 K at 1 kHz) which might be due to the development of the strain at the interfaces of the heterostructure and strong mechanical coupling of ferroelectric phase with the ferromagnetic phase 20,21,40,44 . The increasing of ferroelectric T c towards higher temperature with increasing concentration of NZFO in bulk multiferroic composite has already been reported 15,17 . As in composite structures, ferroelectric and magnetic order parameters are coupled, so both ferroelectric and magnetic properties are affected by the increase/decrease of ferroelectric and magnetic material content.…”

“…5(a) that the magnetization decreases slowly with increase of temperature and vanishes above ~700 K. The ferro-/ferrimagnetic – paramagnetic transition temperature (T c ) is found to be 650 (+/−10) K with a broad transition until 700 K which reveals the existence of short range spin interactions, which results in spin frustration and phase separation. In the existing literature, the reported antiferromagnetic (AFM) - paramagnetic (PM) phase transition of PFN single crystal and bulk ceramics is 140 to 155 K whereas for thin film it is 170–200 K 17,27,28,30,44 . The existence of weak ferromagnetism until 400 K has also been reported 49 .…”

“…Strong ME coupling has been observed in different layered composite structures such as: trilayers of BaTiO 3 /BiFeO 3 /BaTiO 3 , bilayers of PbZr 0.57 Ti 0.43 O 3 /NiFe 2 O 4 , bilayers and superlattices of Ba 0.7 Sr 0.3 TiO 3 /La 0.7 Sr 0.3 MnO 3 , PbZr 0.2 Ti 0.8 O 3 /La 0.8 Sr 0.2 MnO 3 heterostructures, PbZr 0.57 Ti 0.43 O 3 /CoFe 2 O 4 bilayer and multilayers and BaTiO 3 /CoFe 2 O 4 multilayer heterostructures 8,9,13,23,24 . The route to understanding the ME coupling has typically proceeded via first-principle approaches which have yielded a wealth of essential information on the complex interplay of spin-dependent interfacial charge transfer, chemical bonding, and electrostatic screening in these systems 17,18 . Theoretical calculations of the strain-mediated ME coupling necessitate the determination of three factors: (i) the deformations induced in the magnetic phase by the applied magnetic field; (ii) the degree of strain transmission through the interface between the two ferroic constituents of the hybrid system; and (iii) the response of polarization and dielectric susceptibility of the ferroelectric phase to changes in the lattice strain.…”

“…Theoretical calculations of the strain-mediated ME coupling necessitate the determination of three factors: (i) the deformations induced in the magnetic phase by the applied magnetic field; (ii) the degree of strain transmission through the interface between the two ferroic constituents of the hybrid system; and (iii) the response of polarization and dielectric susceptibility of the ferroelectric phase to changes in the lattice strain. In epitaxial heterostructures, the mechanical coupling between the two phases is very strong due to possible perfect mechanical strain transmission 17–21,25 .…”

“…Nickel zinc ferrites (NZFO) are soft magnetic materials with high saturation magnetization, low coercivity, high resistivity, reasonable magnetostriction, low dielectric losses, high dielectric constant and high magnetic Curie temperatures. Ni 0.65 Zn 0.35 Fe 2 O 4 has been chosen for the present work as this composition exhibits the combination of highest saturation magnetization (86 emu/g), high resistivity (~2 × 10 6  Ω cm) and high magnetostriction (10 6  λ 100  = −34) in the entire Ni−Zn series with a magnetic T c of ~663 K 15,17,31–33 .…”