Impedance spectroscopy of Na 0.5 Bi 4.50+x Ti 4 O y (x = ‐0.02, 0, 0.02) ceramics with excellent dielectric properties

• Published in: International journal of applied ceramic technology 2021-09, Vol.18 (5), p.1553-1559
• Main Authors: Du, Yi Ke, Qi, Yi, Liu, Kang Hui, Chen, Ye, Zuo, Yuan Dong, Qin, Lu, Jiang, Chao Bin, Chen, Yong, Shen, Meng, Xiang Huang, Zhao
• Format: Article
• Language: English
• ISSN: 1546-542X; 1744-7402
• DOI: 10.1111/ijac.13735

The electric and dielectric properties of Na 0.5 Bi 4.50+x Ti 4 O y (x = −0.02, 0, 0.02) prepared by conventional mixed oxide route have been investigated by impedance spectroscopy (IS) over a wide temperature range. Single‐phase bismuth layer‐structured perovskite patterns were observed through X‐ray diffraction of the three samples Na 0.5 Bi 4.5 Ti 4 O 15 , Na 0.5 Bi 4.48 Ti 4 O y , and Na 0.5 Bi 4.52 Ti 4 O y . The results show that the relative permittivity (εr) increases with the increase in temperature and reaches its maximum at about 675℃. With the continuous increase in temperature, the permittivity decreases gradually. Both relative permittivity and dielectric loss show great stability at the low‐temperature zone. The ceramic of x = 0.02 with Ea of 1.09 eV has the maximum oxygen ionic transport number between 600 and 800℃ for all samples. And at this time, it has the maximum electrical conductivity. All the results indicated that Na 0.5 Bi 4.50+x Ti 4 O y (x = −0.02, 0, 0.02) ceramics were promising base materials for high‐temperature capacitor because of their high dielectric properties.