An improvement in ferroelectric and ferromagnetic properties of low sintering-temperature (1−x)(0.98(Bi0.5(Na0.78K0.22)0.5−TiO3)−0.02CuO)−(x)NiFe2O4 particulate 0–3 composites

• DOI: 10.1007/s00339-021-04687-3
• Publication Date: 2021-06-23T05:02:44Z
• Authors: Chung Do Pham; Oanh Thi Mai Le; Minh Van Nguyen
• Keywords: Hysteresis; Ferromagnetic material properties

In this study, we report a detail investigation of structural, morphological, ferroelectric, and ferromagnetic properties of low sintering-temperature lead-free particulate composites of (1−x)(0.98(Bi0.5(Na0.78K0.22)0.5−TiO3−0.02CuO)−xNiFe2O4(x = 0–0.15) by using some techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), ferroelectric hysteresis (P-E), piezoelectric constant (d33), and magnetization (M−H) measurements. The formation of two parent materials in single crystal phases without any impurities was demonstrated by XRD. It was interesting that the spontaneous ferroelectric polarization Ps increased with NFO content, reached maximum value at a concentration of 6 mol% of NFO in composite and then declined gradually with further increase of NFO content. Meanwhile, the maximum strain Smax, normalized strain Smax/Emax (d33*), and piezoelectric constant d33 exhibited a gradual reduction as NFO content increased. In M-H hysteresis loop measurements, an improvement in saturation magnetization Ms as well as Mr was observed, albeit not proportional, indicating an increase in ferromagetism of composite.