Multi-sites Doped Perovskite Oxide La_0.5Ba_0.5MnO₃: Crystal Structure, Magnetic And Electrical Properties Research

Perovskite oxide has special physical properties such as magnetic,electrical,optical,acoustic and heat as an important member of the family of inorganic functional materials,At present,such materials have been widely used in field of sensing,information,medicine,energy,catalysis and so on so that it has important research value.The key factor affecting properties ABO₃ perovskite oxides are the B-site ion species and chemical bond parameters.In recent years,the study of perovskite manganese oxide has focused on exploring the structure-activity relationship by replacing or doping B-site ions.However,the research reports less that the introduction of Bi³⁺ ions at the A site and the use of the second Jahn-Teller effect of the ions indirectly affects the manganese ion valence electron environment.In addition,the structure-activity relationship between the crystal structure and the magnetoelectric properties has not been studied by introducing nitrogen ions into the oxygen sites of perovskite manganese oxides.In this paper,a series of perovskite manganese oxide La0.5-x Bix Ba0.5Mn O₃?x = 0 0.15?was synthesized by sol-gel method for the effect of A-site doped.After the Bi³⁺ ions replace La on A site,the sample was converted from tetragonal Pm-3m phase to tetragonal P4 / mmm structure.The magnetic properties of the samples found that the T rose to 320 K by the addition of Bi³⁺ ions,so it is beneficial to the stability of Mn³⁺-O-Mn⁴⁺ spin double exchange structure.However,since the Bi³⁺ ion radius is larger than that of La³⁺ ions,the volume of the unit cell increases and the average bond length of Mn-O becomes longer,which makes the ferromagnetic coupling strength of the sample weaken.In addition,the presence of the antiferromagnetic phase Ba Mn O₃-? and Mn O makes the sample show the magnetic behavior of the cluster glassy state.The DC resistance test showed that the resistivity of the sample LBMO showed a decreasing trend with the addition of Bi³⁺ ions,which was caused by the establishment of long-range electron jump path in the 3d orbit of Mn³⁺ and Mn⁴⁺.The N-doped perovskite manganese oxide La_0.5Ba_0.5Mn O₃-x Nx was synthesized by optimizing the ammoniation temperature,ammoniation time and ammonia ratio.N-doped leads to the conversion of the structural phase of the compound from a pseudo-cubic phase to a monoclinic phase,and the grain has a strong preferential orientation.Mainly due to Mn ion and O ion valence electron chemical environment changes,compound cell parameters of the weak changes and the impact of electron spin.Raman scattering spectroscopy analysis showed that the symmetry stretching vibration of LBMO was obviously broadened by N-doped and shifted to low wavenumbers,and the scattering absorption waves of asymmetric stretching vibration and bending vibration are obviously strengthened.?M-T?and low temperature hysteresis loop?M-H?of LBMO: N samples were consistent with the ferromagnetic system with strong magnetic shock resistance,and under 50 K shows the ferrous behavior.