Microwave-Assisted Solvothermal Route for One-Step Synthesis of Pure Phase Bismuth Ferrite Microflowers with Improved Magnetic and Dielectric Properties

Pravallika Banoth; Arya Sohan; Chinna Kandula; Ravi Kumar Kanaka; Pratap Kollu

doi:10.1021/acsomega.2c00219

Microwave-Assisted Solvothermal Route for One-Step Synthesis of Pure Phase Bismuth Ferrite Microflowers with Improved Magnetic and Dielectric Properties

ACS Omega. 2022 Apr 6;7(15):12910-12921. doi: 10.1021/acsomega.2c00219. eCollection 2022 Apr 19.

Authors

Pravallika Banoth¹, Arya Sohan¹, Chinna Kandula¹, Ravi Kumar Kanaka¹, Pratap Kollu^{1

2}

Affiliations

¹ School of Physics, University of Hyderabad, Prof. C. R. Rao Road, Gachibowli, Hyderabad 500046, Telangana, India.
² CASEST, School of Physics, University of Hyderabad, Prof. C. R. Rao Road, Gachibowli, Hyderabad 500046, Telangana, India.

Abstract

The prototypical plum-free, one-phase multiferric ferrite BiFeO₃ (BFO) is solid, parallel, with a high ferroelectric Curie temperature and Neel temperature and antiferromagnetic and ferroelectric propagation. This work aims to synthesize pure-phase BFO in the quickest possible way. We followed the microwave-assisted solvothermal (MWAST) method to achieve pure-phase BFO in the shortest duration of 3 min. The experiment involves simple optimizations with KOH concentration and microwave power levels. The surface morphology along with magnetic properties of BFO synthesized via the MWAST method are altered with varying KOH concentrations and microwave (MW) power levels. Our X-ray diffraction findings reveal that the pure-phase BFO is formed at 800 W MW power, and the structural characterizations like transmission electron microscopy, field emission scanning electron microscopy with energy-dispersive X-ray analysis have displayed the formation of uniformly distributed spherical microflowers of pure-phase BFO exhibiting a single-crystalline nature. Besides, the magnetic measurements affirmed a reliable weak ferromagnetic behavior (magnetization ∼1.25 emu/g) in BFO synthesized at 800 W MW power. In addition, good dielectric behavior with low dielectric loss was accompanied by frequency-dependent dielectric studies indicating an excellent frequency response of the material, and also the room-temperature ferroelectric properties were studied using a ferroelectric analyzer. The polarization of pure-phase BFO increases with the applied electric field and exhibits unsaturated polarization-electric field loops due to leakage current. Moreover, the Fourier transform infrared spectrum of the synthesized material has indicated the pure-phase BFO, and the Raman data have elucidated the vibrational modes of BFO. Further, the analysis of X-ray photoelectron spectroscopy data has confirmed the presence of fewer Fe²⁺ ions and oxygen vacancies in the pure-phase BFO. Therefore, the collective characterizations and detailed analysis of BFO material have revealed the uniqueness of the MWAST method in producing the pure-phase BFO in 3 min with improved magnetic and dielectric properties, and hence the BFO synthesized via the MWAST method can be a potential candidate for multiferroic applications.