Structural, electrical, and magnetic characterization of (1-x) BaTiO3-x Ni0.6Zn0.4Fe2O4 multiferroic ceramic composites

Abstract

In the present work, pure BaTiO3, pure Ni0.6Zn0.4Fe2O4 and (1-x)BaTiO3-xNi0.6Zn0.4Fe2O4 (where x = 0.15, 0.25 & 0.35) multiferroic composites were synthesized through solid-state sintering scheme. Structural, microstructural, ferroelectric, and ferromagnetic analysis was performed. Both tetragonal perovskite phase (for BaTiO3 ferroelectric phase) and cubic spinel ferrite phase (for Ni0.6Zn0.4Fe2O4 ferromagnetic phase) were simultaneously presented within each composite. The ferrite phase exhibited a smaller crystallite size compared to the ferroelectric phase. All of the composites demonstrated homogenous irregular-shaped grains. The measured average grain size for 0.85BaTiO3-0.15Ni0.6Zn0.4Fe2O4, 0.75BaTiO3-0.25Ni0.6Zn0.4Fe2O4, 0.65BaTiO3-0.35Ni0.6Zn0.4Fe2O4 were 364.14 nm, 378.46 nm and 351.62nm, whereas the density values were 3.04g/cm3, 3.20g/cm3 and 3.13 g/cm3 for x = 0.35, 0.25, 0.15 respectively. However, the heterogenous microstructure was observed for all of the compositions. The composites exhibited an oval-shaped lossy capacitor hysteresis loop. However, 0.75BaTiO3-0.25Ni0.6Zn0.4Fe2O4 composite showed the highest remnant polarization (11.613 μC/cm2) and coercive field value (1.526 kV/cm), ensuring its usability for switching applications. In addition, 0.75BaTiO3-0.25Ni0.6Zn0.4Fe2O4 also exhibited the maximum saturation (Ms= 1.732 emu/g) and remnant magnetization (Mr= 0.025 emu/g) among the composites. Nevertheless, all of the composites derived 'wasp-waisted' hysteresis loops due to the presence of either superparamagnetic (SPM) particles or a mixer of a single domain (SD) and superparamagnetic particles.

Impacts of diffusive ion migration on ferroelectric properties in BaTiO3 composite

“…The larger grains having a well-defined shape and grain boundaries belong to BaM. Surrounding these BaM grains are smaller grains of BTO, consistent with observations in ferroelectric-ferrite composites [27]. The suppression of the growth of the BTO grains is observed which may be due to the difference in the crystal structures of BaM and BTO.…”

Electrical, magnetic and microwave absorption properties of multiferroic NiFe2O4-BaTiO3 nanocomposites

“…This directly affects the ability of the material to absorb and shield microwaves. The intrinsic parameters of the individual ferroic orders [59,60], piezoelectric and magnetostrictive coefficient, and the extent of electromagnetic coupling [26,27] are greatly influenced by grain size. The smaller the grain size will create more grain boundaries.…”

Structural, Dielectric, and Magnetic Properties of Ba2Bi9-xFe5+xTi8O39 Tetragonal Tungsten Bronze Ceramics

“…M s and M r , 4.6 emu g −1 , and 1.935 emu g −1 respectively at 875 °C, which higher than Ba 4 Sm 2 Fe 2 Nb 8 O 30 [72], doped BiFeO 3 (Sm, Co doped x = 0.12) has M s = 0.04 emu g −1 and M r = 0.02 emu g −1 [73]. In addition, 0.75BaTiO 3 −0.25Ni 0.6 Zn 0.4 Fe 2 O 4 also exhibited the maximum saturation (M s = 1.732 emu g −1 ) and remnant magnetization (M r = 0.025 emu g −1 ) [74].…”