Synthesis of highly pure and dense 0.9(KNbO3)‐0.1(BaNi1/2Nb1/2O3‐δ) ceramic with superior magnetic properties

Abstract

AbstractResidual NiO phase is generally detected in 0.9(KNbO3)–0.1(BaNi1/2Nb1/2O3‐δ) (KBNNO) synthesized using NiO as a nickel precursor by solid‐state reaction. In this work, NiO phase is found to exist in the form of the residual NiO particles with a size of 100‐200 nm using energy dispersive X‐ray elemental mapping. These NiO residual particles are eliminated by using nickel acetate as a nickel precursor and a 100% perovskite phase KBNNO is successfully synthesized at as low as 600°C temperature. Furthermore, using the two‐step sintering technique, 100% relative density is achieved in this material. The nickel acetate–based KBNNO shows a robust ferromagnetism with the saturation magnetization of 11.42 memu/g and the remanent magnetization of 3.89 memu/g which is 38 times higher than that of previously reported value in NiO‐based KBNNO. Thus, a highly pure and fully dense KBNNO ceramic with superior magnetic properties is obtained using nickel acetate and by the two‐step sintering method. This is a key step forward in the processing of KBNNO and is likely to have a significant impact on other physical properties of this newly invented and promising photovoltaic perovskite material.