Study of electric conduction mechanisms in bismuth silicate nanofibers

S S Batool,M A Rafiq,Z Imran,Jaweria Ambreen,Safia Hassan,Saira Arif,Kamran Rasool,Mushtaq Ahmad

doi:10.1038/s41598-020-59563-6

Abstract

This work represents the nature of conduction mechanism in bismuth silicate (BiSiO) nanofibers as a function of temperature and frequency. Scanning electron micrographs and X-rays diffraction patterns exhibited the formation of cubic phases of Bi4(SiO4)3 and Bi12SiO20 nanofibers respectively with an average diameter of ~200 nm. Temperature dependent (300 K–400 K) electrical characterization of fibers was carried out in frequency range of ~20 Hz–2 MHz. The complex impedance analysis showed contribution from bulk and intergranular parts of nanofibers in conduction. Moreover, analysis of the Cole-Cole plot confirmed the space charge dependent behavior of BiSiO nanofibers. Two types of relaxation phenomena were observed through Modulus analysis. In ac conductivity curve, step like feature of plateau and dispersive regions were described by Maxwell-Wagner effect while the dc part obeyed the Arrhenius law. However, frequency dependent ac conductivity revealed the presence of conduction mechanism in diverse regions that was ascribed to large polaron tunneling model. Detailed analysis of complex Impedance and ac conductivity measurement showed negative temperature coefficient of resistance for the BiSiO nanofibers. Current-voltage (IV) characteristics represented ohmic conduction; followed by space charge limited current conduction at intermediate voltages. Results from both ac and dc measurements were in good agreement with each other.

Highlights

This work represents the nature of conduction mechanism in bismuth silicate (BiSiO) nanofibers as a function of temperature and frequency
The main goal of the current work is to present an inclusive summary of electrical properties as ac and dc conductivity accompanied by electric modulus variation in BiSiO nanofibers as a function of frequency (1 Hz–2 MHz) and temperature (300 K–400 K)
The morphological studies of the BiSO nanofibers were carried out using Scanning electron micrographs (SEM) and

Summary

Introduction

This work represents the nature of conduction mechanism in bismuth silicate (BiSiO) nanofibers as a function of temperature and frequency. Chemical durability, dielectric strength and interesting structure of BiSiO type materials are proved to be promising for electrical properties This diversity of physical effects makes researchers to grow bismuth silicate from bulk to nanoscale. Among all reported nanostructured materials; one dimensional (1D) nanofibers are most common in electric device fabrications due to their large surface to volume ratio and relatively high crystallinity[7] These 1D nanofibers are frequently used in sensors, nano-electronics tissue engineering, photo-voltaic, nano-photocatalysts and nano-filtration[8].The ac and dc conductivity of the bulk BiSiO materials have been reported[9]. The main goal of the current work is to present an inclusive summary of electrical properties as ac and dc conductivity accompanied by electric modulus variation in BiSiO nanofibers as a function of frequency (1 Hz–2 MHz) and temperature (300 K–400 K). This type of comparison between ac and dc conduction transport on BiSiO nanofibers is rarely been found in literature

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