Studies on novel multiferroic Materials

Abstract

In recent years the A2BB O6 double perovskite (DP) materials have been extensively studied because of their high spin polarization and Curie temperatures (TC) well above room temperature, both the characteristics are very much needed for practical applications like Spintronics. However, the fabrication of DP epitaxial films has proven challenging, mainly for attaining high levels of B/B ordering, which is necessary for their attractive properties. The main goal of this work is to identify some novel multiferroic DPs and to synthesize these materials by gel combustion method. In this work, we synthesized DP materials Bi2FeMoO6, La2MnNiO6, Bi2MnMoO6, Ba2FeMnO6, and Bi2NiCrO6 by gel combustion technique. The structural, morphological, elemental, presence of functional group elements, magnetic and ferroelectric behaviors of these materials were studied using XRD, FESEM, EDAX, FTIR, VSM, SQUID, and PE loop tracer. We synthesized a novel DP Bi2FeMoO6 at first, structural analysis of the material confirms that the material is crystallized in R3C space group with rhombohedral symmetry. FESEM image shows formation of regular shaped nanostructures with aggolomers having particle size of around 50 nm. The presence of functional groups is verified by means of characteristic IR absorption peaks. The material exhibits an excellent multiferroism. Normally, Lanthanum based DP La2MnNiO6 exhibit ferromagnetic property with a Curie temperature of around 280 K. In this work we have prepared La2MnNiO6 nanoparticles by chemical route. In which ethylenediamine is used as a chelating agent. Purity in phase and formation of nanoparticles with aggolomers were confirmed by XRD analysis and FESEM images. The material exhibits room temperature ferromagnetic property and it has a high Curie temperature. Polarization measurement made at room temperature confirms ferroelectric behavior of the material. newline