An investigation of the dielectric behavior of Bi0.7La0.3FeO3 compound under the influence of different calcination temperatures

Abstract

This paper presents the synthesis and characterization of bismuth nanoferrite and lanthanum-doped bismuth nanoferrite (Bi0.7La0.3FeO3). The compounds were synthesized, through the sol-gel method and the doped compound was calcinated at three different temperatures 400 °C, 600 °C, and 800 °C. Following that, the compounds are further analyzed using several characterization methods such as; X-ray diffraction (XRD) analysis confirmed the formation of bismuth ferrite with a distorted perovskite structure and the R3c space group. The crystallite sizes were determined using Sherrer's formula, with bismuth nanoferrite having a size of 14.9 nm and lanthanum-doped bismuth nanoferrite calcinated at different temperatures exhibiting sizes of 13 nm, 17.7 nm, and 20 nm. Fourier transform infrared spectroscopy (FTIR) analysis confirmed the presence of ferrite by observing metal-oxygen (M-O) stretching vibrations in the fingerprint region, with characteristic Fe-O bond peaks in the 430–480 cm−1 range. Ultraviolet-visible spectroscopy revealed promising energy band gaps for the synthesized compounds. Scanning electron microscopy (SEM) was utilized to examine the surface morphology of the compounds, revealing agglomerated structures. Dielectric properties of bismuth nanoferrite have been extensively studied, and lanthanum doping has been shown to improve them. The lanthanum-doped bismuth nanoferrite has a higher dielectric constant than bare bismuth nanoferrite. Additionally, there is less dielectric loss. Hence these results lead to significant potential for many applications, like gas sensors, memory devices, microwave devices, and biomedical applications.

Keywords

• Ferrite
• Sol-gel
• Calcination
• XRD