Structural, magnetic, magneto-dielectric and magneto-electric properties of (1-x) Ba0.85Ca0.15Ti0.90Zr0.10O3 – (x) CoFe2O4 lead-free multiferroic composites sintered at higher temperature

• Published in: Journal of magnetism and magnetic materials 2021-11, Vol.538, p.168243, Article 168243
• Main Authors: Sharma, Sarita, Sharma, Hakikat, Thakur, Shilpa, Shah, J., Kotnala, R.K., Negi, N.S.
• Format: Article
• Language: English
• Subjects: Cobalt ferrites; Composite materials; Coupling coefficients; Dielectric loss; Dielectric properties; Electric contacts; Electric properties; Ferroelectric materials; Ferroelectricity; Grain size; Higher sintering temperature; Lead free; Leakage current; Magnetic properties; Magneto-dielectric; Magneto-electric coupling coefficient; Metallography; Microstructure; MOD; Phase composition; Piezoelectricity; Room temperature; Sintering; Sol-gel; Sol-gel processes
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2021.168243

•Lead-free multiferroic composite systems prepared at higher sintering temperature.•Synthesis of lead-free ferroelectric phase by sol–gel method.•Synthesis of ferrite phase by metallo-organic decomposition method.•Effect of magnetic field on dielectric properties i. e. indirect approach to find magneto-electric coupling response.•High value of magneto-electric coupling coefficient (αME) at higher sintering temperature. Here in this article synthesis of lead-free magnetoelectric composites (1-x) Ba0.85Ca0.15 Ti0.9Zr0.1)O3 - xCoFe2O3 (BCTZ-CFO, x  = 0.4, 0.5, and 0.6) is reported. Structural, magnetic, dielectric, magnetodielectric and magnetoelectric properties of lead-free BCTZ-CFO composites sintered at higher sintering temperature have been systematically investigated. The piezoelectric (ferroelectric) phase has been synthesized using the sol–gel route, while Metallo-organic decomposition (MOD) route was employed to prepare piezomagnetic (ferrite) phase. The structural and microstructural properties were studied using X-Ray diffraction and Scanning electron Microscope respectively acknowledged the presence of two distinct phases as ferrite and ferroelectric in composite samples. The dense microstructure and larger average grain size were observed for samples with higher ferrite phase content. Long-range magnetic order was observed under magnetic study for all-composites. The magnetic properties enhanced for composites prepared with higher ferrite phase content. Dielectric properties were studied at room temperature and enhanced dielectric constant has been observed for samples with higher ferroelectric phase content, while minimum dielectric loss was observed for sample with 50/50 ferrite/ferroelectric phase composition. The magnetodielectric response has been also investigated for all ME composites. Leakage current characterization has been also discussed at and above the room temperature. The magneto-electric coupling response was measured of all composites. The higher value of magneto-electric coupling coefficient has been observed for 0.5BCTZ-0.5CFO composite due to maximum possible ferrite-ferroelectric hetero-structure phase contact area.