Effect of Simultaneous Doping of Pr and Sm on Electrical Conductivity and Relaxation Process in BLSF-SrBi₄Ti₄O₁₅

Abstract

Polycrystalline ceramics SrBi_4-xSm_xTi_3.9Pr_0.1O₁₅ (where x = 0, 0.1, 0.2 and 0.3) were prepared by sol-gel pechini method. The phase formation was confirmed using X-ray diffraction technique and was found to be orthorhombic. Complex impedance spectroscopy (CIS) technique revealed the presence of both grain and grain-boundary effects in the materials. Grain resistance and grain boundary resistance decreases with increasing temperature confirming the NTCR behaviour of the samples. The relaxation times obtained from impedance studies were used to interpret complex impedance nature of the samples. The temperature dependent conductivity obeys the Arrhenius relationship. The impedance studies indicate the non-Debye type of the frequency dispersion for all the samples.

Keywords:

• Sol-gel
• complex impedance spectroscopy
• grain
• grain boundary
• relaxation time

Acknowledgments

The authors are thankful to Dr. G. Ravi Chandra ARCI, Hyderabad for providing SEM and EDS facilities.