Journal Article

Role of annealing conditions on the ferromagnetic and dielectric properties of La2NiMnO6

Ayyub, P., Jayakumar, O.D., Chatterjee, S., Sayed, Farheen N., Achary, S.N., Deshpande, S.K., Krishna, P.S.R., Tyagi, A.K.

2011

Overview

La2NiMnO6 (LNMO) was prepared by a combustion method followed by heating at high temperature. Subsequently, the preformed LNMO was annealed in air, oxygen, or N2 atmosphere and characterized by powder x-ray diffraction (XRD), neutron diffraction, superconducting quantum interference device magnetometry, and dielectric analysis. Structural studies by XRD and neutron diffraction revealed the coexistence of partially cation disordered monoclinic (31%) and rhombohedral (69%) phases in the sample annealed in air. However, the sample annealed in oxygen shows about 50:50% of monoclinic and rhombohedral phases. Relaxor-like behavior with relative permittivity of the order of 104 was observed in the sample annealed in air, while relative permittivity decreases to about 200 in samples annealed in oxygen atmosphere. The magnetic properties indicate a well-defined ferromagnetic phase in the oxygen-annealed sample compared to a feeble ferromagnetic signature in the air-annealed one. The dielectric and ferromagnetism of LNMO samples have been related to formation and annihilation of oxygen vacancies.

• Publisher: Cambridge University Press,Springer International Publishing,Springer Nature B.V
• Subject: Annealing / Applied and Technical Physics / Biomaterials / Crystal structure / Dielectric properties / Electrons / Ferromagnetic phases / Ferromagnetism / High temperature / Inorganic Chemistry / Magnetic measurement / Magnetic properties / Materials Engineering / Materials research / Materials Science / Nanotechnology / Neutron diffraction / Neutrons / Oxygen / Permittivity / Superconducting quantum interference devices / Thermal analysis / Thin films / X ray powder diffraction / X-ray diffraction