Investigation of Structural, Electrical, and Vibrational Properties of Bi1.98A0.02Fe4O9 (A = Ba, Ce) Multiferroic Ceramics

Ashwini Kumar,Poorva Sharma,Jingyou Tang,Nikhil Bhardwaj,Guolong Tan,Francisco Javier Fernández Fernández

doi:10.1155/2021/5597415

Abstract

In this paper, we report the synthesis, phase formation, and basic characterization of polycrystalline Bi2Fe4O9, Bi1.98Ba0.02Fe4O9, and Bi1.98Ce0.02Fe4O9 samples prepared by the sol-gel technique. The crystal structure of the prepared samples has been characterized by means of X-ray diffraction and Raman scattering spectroscopy. All the obtained XRD peaks can be indexed to the orthorhombic Pbam structure and reveal the formation of Bi2Fe4O9. The Raman spectrum identifies Ag, B2g, and B3g active optical phonon modes. The crystallite size and morphology of the nanoparticles have been analyzed using scanning electron microscope (SEM). Dielectric constant (ε′) decreases as the frequency increases, and it is constant at the higher frequency region which can be explained based on the ionic conduction phenomenon in the low frequency region. The ε′ values of Bi2Fe4O9(650–850), Bi2Fe4O9(800–850), Bi1.98Ba0.02Fe4O9, and Bi1.98Ce0.02Fe4O9 samples at 10 Hz frequency are about 37, 75, 90, and 393, respectively. The observed properties signify that these materials are very useful in advanced technological and practical applications.

Highlights

Advances in Materials Science and Engineering loops
In an another recent work, Bi2Fe4O9 and Gd-doped Bi2Fe4O9 samples were synthesized by solid-state mechanochemical ball milling technique, and it revealed the remarkable changes in magnetic and dielectric properties for Gd-doped Bi2Fe4O9 samples due to electronhole hopping mechanism and spin-orbital coupling through D-M interaction
In order to obtain a suitable ceramic phase, we examined the phase formation and physical properties and the glassy precursor was subjected to different heat-treatments at different temperatures and for different durations

Summary

Introduction

Advances in Materials Science and Engineering loops. Bi2Fe4O9 with a band gap of about 1.53 eV presents catalytic activity under visible light irradiation [14, 15]. Ey observed the significant enhancement in remnant magnetization, saturation magnetization, dielectric constant as well as conductivity due to substitution of Ba content in Bi2Fe4O9 [21] In an another recent work, Bi2Fe4O9 and Gd-doped Bi2Fe4O9 samples were synthesized by solid-state mechanochemical ball milling technique, and it revealed the remarkable changes in magnetic and dielectric properties for Gd-doped Bi2Fe4O9 samples due to electronhole hopping mechanism and spin-orbital coupling through D-M interaction. They found that the Gddoped Bi2Fe4O9 samples had much higher photocatalytic degradation of MB dye than the undoped Bi2Fe4O9 [22]. We report the phase formation, physical properties, and vibrational properties of polycrystalline Bi2Fe4O9 ceramic synthesized

Experimental Details

Results and Discussion

Conclusions