Master'S Project
Master's thesis title: Investigation of Structural and Magnetic Properties of La2NiMnO6"Abstract: Existence of multiferroicity in single phase is extremely rare and tunability of dielectric property with magnetic field in La2NiMnO6 (LNMO) make it as a potential multiferroic candidate which reported to have ferro-elasticity and a ferromagnetic transition temperature of 280K . Double perovskite LNMO is synthesised by different techniques such as sol- gel, co- precipitation and Hydrothermal. Furthermore, it is characterized by powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X ray spectroscopy (EDX), Raman spectroscopy and physical property measurement system for magnetometry. Structural analysis showed the presence of 73.6% Monoclinic and 26.4% Rhombohedral phases at room temperature. The magnetisation obtained to be 4.197(5T) μB/f.u. This value is lower than the theoretical spin only value 5 μB/f. u, implies Ni/Mn anti-site disorder (8 %). Raman peaks corresponding to anti-stretching (530 cm-1) and stretching (674 cm-1) has been observed, which are in well- agreement with literature . Subsequently, pH dependence of rate of reactions has been studied. Found that, La2NiMnO6 has less impurities in extreme mediums (pH1, pH 10). We attribute this effect to the blocking of impurity forming pathways in presence of donor/acceptor protons.
