The influence of K substitution on the structural, optical and magnetic properties of LaFeO3 perovskites. (1st February 2022)

• Record Type: Journal Article
• Authors: Gomaa, M.M.; Sayed, M.H.; Abo El-Soud, A.M.; Boshta, M.
• Is Part Of: Solid state communications. Volume 342(2022)
• Publication Date: 2022-02-01
• Subjects: La1-xKxFeO3 (0.0≤ x ≤ 0.3) oxides -- K substitution -- Structural properties -- Diffuse reflectance -- Bandgap energy -- Magnetic properties; Solid state chemistry -- Periodicals; Solid state physics -- Periodicals; Chimie de l'état solide -- Périodiques; Physique de l'état solide -- Périodiques; 530.41
• DOI: 10.1016/j.ssc.2021.114615
• Languages: English
• ISSNs: 0038-1098

Abstract

Abstract: Single-phase lanthanum ferrite oxides doped potassium (K) with various composition of La1-x Kx FeO3 (0.0≤ x ≤ 0.3) were successfully prepared using cost-effective precursors via a solid-state reaction route. The influence of K substitution at La site of LaFeO3 on its structural, optical, and magnetic properties have been studied. X-ray diffraction (XRD) results indicated that all synthesized samples were a polycrystalline single-phase orthorhombic perovskite structure, with peaks shifting to higher Bragg angles by increasing K amount. Direct bandgap energy (Eg ) of La1-x Kx FeO3 samples was dramatically decreased from 2.28 eV to 1.22 eV with increasing the amount of K substitution in the LaFeO3 Lattice. Magnetic hysteresis loops show that the obtained samples have a ferromagnetic response at room temperature with enhanced magnetization from 0.16 to 1.72 emu/g with increasing the K concentration. The changes of the optical and magnetic properties attributed to the crystal structure defects resulting from the replacement of La 3+ by K 1+, which cerate oxygen vacancies due to the variation in the valence state ratio of Fe 4+ /Fe 3+ . The enhanced magnetization and tunable Eg in the visible region make La1-x Kx FeO3 (0.0≤ x ≤ 0.3) promising materials for environmental applications such as solid oxides fuel cells (SOFC) and photocatalysis. Highlights: Single-phase orthoferrite perovskite La1-x Kx FeO3 (0.0≤ x ≤ 0.3) were fabricated using solid-state reaction. The influence of K substitution on the structural, optical, and magnetic properties of LaFeO3 perovskite were investigated. The direct bandgap energy of the samples was decreased from 2.28 eV to 1.22 eV with increasing the amount of K substitution. The saturation magnetization Ms of the doped La0.7 K0.3 FeO3 sample was about ten times larger than pure LaFeO3 sample.