Synthesis, structure and magnetic characterization of orthoferrite LaFeO3 nanoparticles

Abstract

Single-phase lanthanum orthoferrite (LaFeO3) was prepared by an auto-combustion method. The analysis of synchrotron room temperature X-ray diffraction (XRD) data confirmed the orthorhombic LaFeO3 perovskite of space group Pnma without any impurity phase. The Scherrer's formula and Williamson-Hall plot based on XRD data were employed to estimate the crystallite size of the prepared sample. For a deeper insight into the crystal structure, high-resolution transmission microscopy imaging (HRTEM) was performed. The estimated values of crystallite size from HRTEM and synchrotron XRD data were coincident. The HRTEM images confirmed the polycrystalline nature of the prepared sample through the obvious lattice planes which are related to (121) plane. Furthermore, the M(H) hysteresis loop of the investigated sample was characterized by a vibrating sample magnetometer (VSM). The magnetic properties obtained through analyzing the magnetization versus temperature M(T) and magnetization versus magnetic field M(H) curves indicated that LaFeO3 possessed weak ferromagnetism at room temperature.

Autocombustion‐Promoted Synthesis of Lanthanum Iron Oxide: Application as Heterogeneous Catalyst for Synthesis of Piperidines, Substituted Amines and Light‐Assisted Degradations

“…It is known that the ferromagnetism arises because of the supper exchange (SE) interaction of the Fe 3 + -O 2À -Fe 3 + ions which produce a ferromagnetic shell model at the surface of the particle due to disordered spins. [1] The value of saturation magnetization (M S ) of the uncalcinated sample and the sample calcined at 700°C were observed to be 0.0040 emu/g and 0.0054 emu/g respectively. The slight increase in M S values with increase in calcination temperature can be due to (i) the formation of oxygen vacancies which resulted to the existence of Fe 3 + ions (ii) the conversion of Fe 3 + ions to Fe 4 + ions (iii) the shrinkage of the spin spiral structure.…”

“…Recently, Perovskite type oxides having the general formula ABO 3 where A is usually a rare-earth metal cation and B is 3d transition metal cation have attracted many researchers because of their well-defined structure and high thermal stability. [1] Hypothetically, these perovskite oxides are known to exist in the cubic structure. [2] But in reality distortions in cubic structure were found to be there due to the occupancy of the differently sized cations possessing different valencies thus creating oxygen deficiency or excess.…”

Multiferroicidad en LaFeO3 sintetizada mediante molienda de alta energía

“…Dentro de los multiferroicos destacan los denominados de segunda generación, los cuales se basan en materiales tipo perovskita de estructura ortorrómbica (Wang et al, 2017) y se caracterizan por su facilidad en su síntesis, sin la presencia de fases secundarias, como ocurre durante la síntesis de la BiFeO3 (Pedro et al, 2018). De entre todas las perovskitas ortorrómbicas, destaca la LaFeO3, debido a que es un material muy estable químicamente (Abbas et al, 2018) y tiene muchos sitios de dopaje, lo cual implica que se pueden modular sus propiedades ferroicas (Triyono et al, 2020).…”