Anomalous Dielectric behavior and Correlation of Barrier Hopping Mechanism with Ferroelectricity in Solvent Assisted Phase Pure Bismuth Iron Oxide Nanoparticles

Publication date: Available online 12 July 2019Source: Materials Research BulletinAuthor(s): M Tahir, Saira Riaz, Naveed Ahmad, Usman Khan, Shahid Atiq, M Javaid Iqbal, Shahzad NaseemAbstractPhase pure bismuth iron oxide (BiFeO3) nanoparticles (NPs) are synthesized using sol-gel route; acetic acid (AA) and ethylene glycol (EG) are used as solvents. Nanoparticles synthesized using AA as solvent result in amorphous behavior under as-synthesized condition. Phase pure BiFeO3 is obtained after calcination at 200 °C. Whereas, mixed BiFeO3 and Bi2Fe4O9 phases are observed after calcination at 300 °C. Nanoparticles synthesized using EG as solvent result in phase pure BiFeO3 even under as-synthesized conditions. Strengthening of phase pure BiFeO3 is observed after calcination at 300 °C. TEM result shows spherical morphology of nanoparticles with average size ˜12 nm after calcination at 300 °C using EG as solvent. Higher value of dielectric constant (i.e. ˜1050) and low tangent loss (i.e. ˜0.001), at log f = 7.3, are observed for EG based nanoparticles. Variation in conductivity with change in temperature is studied in detail using Jonscher’s power law. AC electrical conduction is associated with correlated barrier-hopping mechanism. Bismuth iron oxide nanoparticles exhibit room temperature ferroelectricity for both of the solvents used i.e. acetic acid and ethylene glycol. Low electrical coercivity and maximum polarization (Pmax˜12.22 µC/cm2) are observed for ...
Source: Materials Research Bulletin - Category: Materials Science Source Type: research