Phase evolution, microstructure and dielectric properties of electrospun Ba(Zr0.2Ti0.8)O3–0.5(Ba0.7Ca0.3)TiO3 |
Amir Mahdi Molavi, Parvin Alizadeh |
Department of Materials Science and Engineering, Faculty of Engineering and Technology, Tarbiat Modares University, P. O. Box, 14115-143 Tehran, Iran |
|
Received: August 24, 2020; Revised: October 16, 2020 Accepted: October 20, 2020. Published online: March 31, 2021. |
|
|
ABSTRACT |
Ba(Zr0.2Ti0.8)O3–0.5(Ba0.7Ca0.3)TiO3 or simply BZT-0.5BCT has attracted increasing attention due to its excellent ferroelectric properties and lack of lead. BZT-0.5BCT nanofibers were fabricated by sol–gel assisted electrospinning and post-calcination process. Different types of analysis were utilized to study phase evolutions and characterization of calcined fibers. TGA indicated three stages of polymer decomposition at temperatures below 500 °C. FTIR spectroscopy revealed the presence of acetate salts of inorganic precursors in electrospun fibers. Also, it was determined that the formation of oxides started at temperatures around 300 °C and intensified with a rise in temperature. In keeping with DSC and FTIR results, XRD analysis revealed a low crystallization temperature of 550 °C for the perovskite phase. The room-temperature Raman spectroscopy demonstrated the coexistence of both orthorhombic and tetragonal phases at 900 °C and higher temperatures. SEM images illustrated the stability of fibrous morphology up to 1000 °C. High-temperature XRD showed that the curie temperature of nanofibers is between 120 and 150 °C. The dielectric constant of calcined fibers at 900 °C was measured to be 2283. |
Key words:
Lead-free perovskite · Electrospinning · Nanofiber · BZT-0.5BCT · Phase evolution |
|
|
|