Dielectric relaxation and conduction mechanism of complex perovskite Ca0.90Sr0.10Cu3Ti3.95Zn0.05O12 ceramic. Issue 6 (15th April 2018)

• Record Type: Journal Article
• Authors: Rani, Suman; Ahlawat, Neetu; Punia, R.; Sangwan, Kanta Maan; Rani, Sunita
• Is Part Of: Ceramics international. Volume 44:Issue 6(2018)
• Page Start: 5996
• Page End: 6001
• Publication Date: 2018-04-15
• Subjects: Calcium copper titanate -- Rietveld refinement -- Dielectric properties -- OLPT model; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2017.12.187
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: In this work, Sr and Zn co-doped calcium copper titanate having nominal formula Ca0.90 Sr0.10 Cu3 Ti3.95 Zn0.05 O12 has been synthesized and systematically studied for structure, dielectric and electrical properties. The phase purity of the prepared composition has been confirmed by X-ray diffraction (XRD) pattern and various structural parameters are presented here with Rietveld refinement data. The Scanning electron microscopy (SEM) image revealed the presence of homogeneous fine-grained microstructure investigated in the prepared ceramic. The impedance data well fitted with 2 R-CPE model confirmed the non-ideality of the system. Dielectric studies have shown the existence of two relaxation processes in low and high frequency domains. Low frequency dielectric response proposed as a combination of Maxwell-Wagner relaxation and intrinsic defect (Vo ++ ) while high frequency behavior has been interpreted in terms of polaronic relaxation caused by hopping process of an electron between Ti 3+ and Ti 4+ states. The frequency dependent behavior of conductivity has been well fitted to Dong's model and interpreted in term of Overlapping Large Polaron Tunneling (OLPT) mechanism. The various parameters; relaxation angular frequency (ω1 ) of Debye process, ionic hopping frequency (ω2), dc conductivity (σo ), cole- cole parameter (α) and frequency exponent (s) have been determined by Dong's Model fitting.