Find in Library
Search millions of books, articles, and more
Indexed Open Access Databases
Enhanced Magnetic Properties of Co-Doped BiFeO<sub>3</sub> Thin Films via Structural Progression
oleh: Liang Bai, Mingjie Sun, Wenjing Ma, Jinghai Yang, Junkai Zhang, Yanqing Liu
Format: | Article |
---|---|
Diterbitkan: | MDPI AG 2020-09-01 |
Deskripsi
Co<sup>3+</sup> doping in BiFeO<sub>3</sub> is expected to be an effective method for improving its magnetic properties. In this work, pristine BiFeO<sub>3</sub> (BFO) and doped BiFe<sub>1-x</sub>Co<sub>x</sub>O<sub>3</sub> (BFC<sub>x</sub>O, x = 0.01, 0.03, 0.05, 0.07 and 0.10) composite thin films were successfully synthesized by a sol–gel technique. XRD and Raman spectra indicate that the Co<sup>3+</sup> ions are substituted for the Fe<sup>3+</sup> ion sites in the BFO rhombohedral lattice. Raman vibration of oxygen octahedron is obviously weakened due to the lattice distortion induced by the size mismatch between two B-site cations (Fe<sup>3+</sup> and Co<sup>3+</sup> ions), which has an impact on the magnetic properties of BFC<sub>x</sub>O. SEM images reveal a denser agglomeration in Co-doped samples. TEM results indicate that the average size of grains is reduced due to the Co<sup>3+</sup> substitution. XPS measurements illustrate that the replacement of Fe<sup>3+</sup> with Co<sup>3+</sup> effectively suppresses the generation of oxygen defects and increases the concentration of Fe<sup>3+</sup> ions at the B-site of perovskite lattice. Vibrating sample magnetometer (VSM) measurements show that the remanent magnetization (Mr) of BFC<sub>0.07</sub>O (3.6 emu/cm<sup>3</sup>) and the saturation magnetization (Ms) of BFC<sub>0.10</sub>O (48.84 emu/cm<sup>3</sup>) thin film both increase by approximately two times at room temperature, compared with that of the pure BFO counterpart.