Ferromagnetism and optical properties of La1 − xAl x FeO3 nanopowders

Abstract

La1 − x Al x FeO3 (x = 0.0, 0.05, 0.1, 0.2, 0.3, 0.4, and 0.5) nanopowders were prepared by polymerization complex method. All prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and UV-vis spectrophotometry (UV-vis). The magnetic properties were investigated using a vibrating sample magnetometer (VSM). The X-ray results of all samples show the formation of an orthorhombic phase with the second phase of α-Fe2O3 in doped samples. The crystallite sizes of nanoparticles decreased with increasing Al content, and they are found to be in the range of 58.45 ± 5.90 to 15.58 ± 4.64 nm. SEM and TEM images show the agglomeration of nanoparticles with average particle size in the range of 60 to 75 nm. The FT-IR spectra confirm the presence of metal oxygen bonds of O-Fe-O and Fe-O in the FeO6 octahedra. The UV-vis spectra show strong absorption peaks at approximately 285 nm, and the calculated optical band gaps are found to be in the range of 2.05 to 2.09 eV with increasing Al content. The M-H loop of the pure sample is antiferromagnetic, whereas those of the doped samples tend to be ferromagnetic with increasing Al content. The magnetization, remanent magnetization, and coercive field of the Al-doped sample with x = 0.5 are enhanced to 1.665 emu/g, 0.623 emu/g, and 4,087.0 Oe, respectively.

Effect of different synthetic routes on the structural, morphological and magnetic properties of Ce doped LaFeO3 nanoparticles

“…nanoparticles obtained by us is higher whereas H c is lower than Zn doped LaFeO 3 synthesized by co-precipitation method as reported by Mukhopadhyay et al [49]. Similarly, Yutana et al [36] studied the enhancement of magnetic properties of LaFeO 3 synthesized by polymerizationcomplex method at higher doping of Al (x=0.5) and the M s (1.66 emu/g) is comparable with our result at lower doping of Ce. Thus, it has been observed that the nature of doped metal ion and choice of synthetic route can significantly affect the magnetic parameters of nanomaterials.…”

One-Step Soft Chemical Synthesis of Magnetite Nanoparticles under Inert Gas Atmosphere. Magnetic Properties and In Vitro Study

“…All samples exhibit similar absorption bands around 579–602 cm −1 , which can be attributed to the Fe-O stretching vibration ( Figure 1 a,b), confirming magnetite presence [ 35 , 36 , 37 ]. In addition, weak absorption bands are observed at 1628 cm −1 ( Figure 1 a), in the case of samples prepared at 100 °C (S1–S3), which could be attributed to the bending mode of O-H bond or to the carbonate groups from atmospheric CO 2 [ 35 , 36 ].…”

Physico-chemical properties and catalytic activity of the sol-gel prepared Ce-ion doped LaMnO3 perovskites

“…The experimentally assessed direct energy band gaps of all perovskite nanomaterials are 1.15, 1.31, 1.34 and 1.32 eV for LaMnO 3 , La 0.95 Ce 0.05 MnO 3 , La 0.93 Ce 0.07 MnO 3 , and La 0.90 Ce 0.10 MnO 3 perovskites, respectively. An observed increase band gap energy with increasing the Ce 3+ ion substitution quantity into the LaMnO 3 crystal lattice, which is attributable to the Burstein-Moss effect 28,30–32 .

Figure 5( a) UV/Vis absorption spectra and ( b ) The plot of (αh ν ) 2 vs. photon energy(h ν ) LaMnO 3 , La 0.95 Ce 0.05 MnO 3 , La 0.93 Ce 0.07 MnO 3 and La 0.90 Ce 0.10 MnO 3 nanoparticles.

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