Ordering effect on the electrical properties of stoichiometric Ba3CaNb2O9-based perovskite ceramics

Author(s)

Rodrigues, J. E. ; Bezerra, D. M. ; Hernandes, A. C.

• Document type: Journal article
• Source: CERAMICS INTERNATIONAL; v. 43, n. 16, p. 14015-14022, NOV 2017.
• Web of Science Citations: 4

Abstract

Cation ordering is the most common phenomenon detected in A(3)B'B `' O-2(9)-based complex perovskites. Some important physical features of this system are due to the B-site ordering at long and short range. For microwave applications as filters and resonators, the 1:2 order is more appropriate. Otherwise, the oxygen vacancies and 1:1 order are considered the main factors behind the excellent performance of nonstoichiometric A(3)B'B1+x `' O-2-x(9-delta)-based ceramics as proton conductors. Until now, however, there are no available reports regarding the isolated effects of B-site ordering at long range on the electrical properties of stoichiometric systems. This work reports the preparation of 1:1 and 1:2 ordered Ba3CaNb2O9 ceramics. Here, we combine the Raman scattering and group-theory calculations to distinguish the fingerprints of the 1:1 and 1:2 orders. The electrical properties of the ordered Ba3CaNb2O9 are analyzed in terms of a phenomenological model based on the parallel combination of a resistor, constant phase element, and capacitor. In particular, the conductivity relaxation ascribed to the grains is due to the oxygen vacancies. Besides, we found that the 1:1 order increases the dc conductivity compared to the 1:2 order. (AU)

• FAPESP's process: 08/57872-1 - National Institute for Materials Science in Nanotechnology
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC