Synthesis and characterization of composite MgFe2O4–BaTiO3 multiferroic system

Abstract

Multiferroic ceramics with the general formula (x)MgFe2O4–(1−x)BaTiO3 (x=0.4, 0.5, and 0.6) were synthesized by solid-state sintering process. From the x-ray diffraction analysis, it was observed that almost no chemical reaction occurs between the ferrite and the ferroelectric materials used to form the diphase composite systems. No impure phase was observed in all the sintered composite systems. Leakage current density, ferroelectric properties and dielectric properties were found to improve with the addition of the ferroelectric phase. For the composite with the least amount of ferrite, the values of remnant polarization (2Pr) before and after dc magnetic poling at 7kOe for 1h were found to be 1.35 and 2.12μC∕cm2, respectively. This showed marked improvement as high as 57% and confirmed the coupling of the electrical dipoles with the magnetic field applied. All the studied composite systems proved to be multiferroic in nature. The highest magnetoelectric coupling coefficient of 50.2mV∕cmOe was measured at dc magnetic field of 10kOe along with ac frequency of 50Hz at room temperature for the 0.6MgFe2O4–0.4BaTiO3 composite system. Magnetoelectric effect at resonance frequency increases by a factor of 80 compared to the other frequencies for such composite systems.

Multiferroic composites in nano–microscale with non-solid solution by Co-ferrite and (K0.5Na0.5)NbO3-based ferroelectric matrix

“…A dilution effect is observed in Fig. 6b [25]. The calculated saturation magnetic moment (M s ) and remanent magnetization (M r ) are shown in the inset of Fig.…”

Magnetic properties and magneto electric effect in ferroelectric rich Ni0.5Zn0.5Fe2O4+BPZT ME composites

“…The ME coefficient of the composites was measured as a function of DC magnetic field [15,16]. Prior to this it is necessary to pole the sample electrically and magnetically.…”

In situ preparation of CoFe2O4–Pb(ZrTi)O3 multiferroic composites by gel-combustion technique

“…In addition, high dielectric losses (tan δ 1) at room temperature were normally found. [10][11][12][13][14][15][16] These were considered as originating mainly from microstructural effects and to the presence of secondary phases formed during the sintering step. In the large majority of publications reporting data on composite ceramics, a direct mechanical mixing of the ferroelectric and magnetic phases separately prepared was employed for producing the composite.…”