High temperature impedance spectroscopy of barium stannate, BaSnO3

Bulletin of materials science

Shail Upadhyay¹ 

[1] Department of Physics, Institute of Technology, Banaras Hindu University, Varanasi 221 005, India$$Department of Physics, Institute of Technology, Banaras Hindu University, Varanasi 221 005, IndiaDepartment of Physics, Institute of Technology, Banaras Hindu University, Varanasi 221 005, India$$

关键词: Ceramics;    oxides;    infrared spectroscopy;    electrical properties;    electrical conductivity.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

Polycrystalline powder of BaSnO₃ was prepared at 1300 °C using a high-temperature solid-state reaction technique. X-ray diffraction analysis indicated the formation of a single-phase cubic structure with lattice parameter:= (4.1158 ± 0.0003) Ã�?. The synthesized powder was characterized using X-ray diffraction (XRD) scanning electron micrographs, energy dispersive X-ray analysis, differential thermal analysis, thermogravimetric analysis and Fourier transform infrared techniques. Electrical properties were studied using a.c. impedance spectroscopy technique in the temperature range of 50â€�??650 °C and frequency range of 10 Hzâ€�??13 MHz. The complex impedance plots at temperature â‰�? 300 °C show that total impedance is due to the contributions of grains, grain boundaries and electrode. Resistance of these contributions has been determined. Variation of these resistances with temperature shows the presence of two different regions with different slopes. The nature of variation for the above three resistances, in both the temperature regions confirms that conducting species (phases) responsible for grain, grain boundaries and electrode are the same. Based on the value of activation energy, it is proposed that conduction via hopping of doubly ionized oxygen vacancies_{o}$) is taking place in the temperature region of 300â€�??450 °C, whereas in the temperature region of 450â€�??650 °C, hopping of proton, i.e. ions occurs.

【 授权许可】

Unknown