Theoretical and experimental investigation of the structural and magnetic properties of La 2 NiMnO 6

This work investigated in theoretical and experimental forms the structural and magnetic properties of the double perovskite La 2 NiMnO 6. The nanoparticles were prepared through the method of coordination chemistry using chitosan, and the crystal structure is monoclinic with P2 1 /n space group. The ab initio calculation was applied successfully to investigate this material's structural, electronic, and magnetic effects. The calculation of the geometry optimization gave support to the understanding of the experimental results, which suggest the formation of the crystalline structure with deformation in the octahedral sites of Ni/Mn. The magnetization measures suggest ferromagnetic ordering of the Ni 2+ -O-Mn 4+ phase and anti-site disorder Ni 2+ -O-Ni 2+ or Mn 4+ -O-Mn 4+ to T < 150 K, T C  ≈ 150 K and paramagnetic behaviour in ambient conditions. With the calculation of the electronic structure and the state density was possible to observe the semiconductor feature of the material. The spins state reveals a ferromagnetic coupling between the (3d 8 ) Ni 2+ and (3d 3 ) Mn 4+ ions. Both results indicate this system’s complexity, making it of great interest in basic research and practical applications.