National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 210093, China
Adv. Mater. Lett., 2019, 10 (12), pp 874-879
Publication Date (Web): May 18, 2019
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Double-perovskite structured multiferroic Bi2FeMnO6 (BFMO) ceramics synthesized via solid-state reaction route at 880oC for 3 h, crystallized in a distorted rhombohedral structure with R3c space group. Their lattice parameters in the hexagonal system were determined to be a = 5.571 Å and c = 13.191 Å. SEM images show that the BFMO ceramic grains exhibit spherical morphology with an average size of 6.70 mm. Their atomic ratio of Bi:Fe:Mn was determined to be 2.07:1.02:1.00, close to the nominal value of 2:1:1. Raman spectra have verified the vibrational frequencies in the BFMO ceramics, and only 11 Raman active modes are observed. The less observed Raman modes in the BFMO ceramics compared with the theoretical group analyses, can be ascribed to the small correlation field splitting of the ceramic samples due to their polycrystalline nature. BFMO ceramics exhibit almost frequency-independent dielectric behavior in a frequency range of 500 - 106 Hz at room temperature. Their dielectric constant and dielectric loss were measured to be 700 and 0.03 at 106 Hz, respectively. The piezoelectric moduli d33 of the poled BFMO ceramics was measured to be 56 pC/N, which is two times larger than that reported for BiFeO3 thin film (d33 ≅ 25 pC/N). © VBRI Press.
Double perovskite oxides, Bi2FeMnO6 multiferroic ceramics, Raman spectra, dielectric and piezoelectric properties, microstructural characterization