Influence of Nd2O3 Doping on the Reaction Process and Sintering Behavior of BaCeO3 Ceramics
Journal
Journal of the American Ceramic Society
Journal Volume
77
Journal Issue
10
Pages
2523-2528
Date Issued
1994
Author(s)
Abstract
The influence of Nd2O3 doping on the reaction process and sintering behavior of BaCeO3 is investigated. Formation of BaCeO3 is initiated at 800°C and completed at 1000°C. When Nd2O3 is added to the starting materials, the formation of BaCe1–xNdxO3–δ is delayed and the temperature for complete reaction is increased to 1100°C. Only a BaCe1‐xNdxO3–δ solid solution with an orthorhombic crystal structure is present in the specimens for x ≤ 0.1. A secondary phase rich in Ce and Nd is formed within grains and at grain boundaries, when the Nd2O3 content is greater than the solubility limit (x ≥ 0.2). Pure BaCeO3 is difficult to sinter, even at 1500°C, and only a porous microstructure could be obtained. However, doping BaCeO3 with Nd2O3 markedly enhances its sinterability. The enhancement of the sinterability of Nd2O3‐doped specimens at x ≤ 0.1 is attributed to the increase in the concentration of oxygen ion vacancies, which increases the diffusion rate. At x ≥ 0.2, the grain size is abnormally coarsened, which is caused by the formation of a liquid phase. While this liquid phase accelerates sintering, its beneficial effect on densification is counteracted by the segregation of the secondary grain‐boundary phase which inhibits sintering. Copyright © 1994, Wiley Blackwell. All rights reserved
SDGs
Type
journal article