Influence of Synthetic Conditions on the Crystal Structure, Optical and Magnetic Properties of o-EuFeO3 Nanoparticles

Abstract

In this paper, powders consisting of o-EuFeO3 nanoparticles were obtained by the co-precipitation method using two different precipitating agents (NH3 and (NH4)2CO3 solutions; corresponding products were denoted as samples S.1 and S.2, respectively) and followed by annealing for 1 h at 750, 850, and 950 °C. The magnetic, optical, and physicochemical characteristics of S.1 and S.2 were evaluated by means of EDXS (energy dispersive X-ray spectroscopy), PXRD (powder X-ray diffraction), TG/DSC (thermogravimetry/differential scanning calorimetry), FTIR (Fourier-transform infrared spectroscopy), TEM (transmission electron microscopy), UV-Vis DRS (Ultraviolet–Visible diffuse reflectance spectroscopy), and VSM (vibrating-sample magnetometry). The o-EuFeO3 structure was shown to be stable at annealed temperatures, and t = 850 °C is recommended for synthesizing such substances. The average size of o-EuFeO3 crystals is around 27 (S.1) and 34 nm (S.2). The results revealed a homogeneous distribution of the main elements on the samples’ surfaces, with morphology consisting of isometric and highly agglomerated nanoparticles. The bandgap value (Eg) of the synthesized samples was 2.31 (S.1) and 2.39 eV (S.2). Besides, these nanoparticles appeared to possess paramagnetic behavior.

Structural, Optical, and Magnetic Properties of o‐TbFeO3 Nanomaterials Synthesized by the co‐Precipitation Method

“…In this work, all of the samples are characterized by low values of coercive field (H c � 5-11 • 10 À 3 Oe), remanent magnetization (M r � 1.54-3.60 • 10 À 6 emu • g À 1 ), and relatively high values of net magnetization (M n � 2.06-2.40 emu • g À 1 ), as compared to other materials in the literature (Table 1). These magnetic properties are very similar to those of the EuFeO 3 -850 system prepared by the co-precipitation method using NH 3 and (NH 4 ) 2 CO 3 solutions as precipitating agents, [28] although the average crystallite size obtained in this work is 2.8 times smaller than that of the TbFeO 3 -850 sample. Among the different rareearth orthoferrites shown in Table 1, HoFeO 3 -850 appears to have the highest M n value of 4.65 emu • g À 1 , while the lowest belongs to LaFeO 3 -850 (0.24 emu • g À 1 ) and PrFeO 3 -850 (0.19 emu • g À 1 ).…”

“…The particle size, morphology, crystal structure, and type of R elements can affect the properties of the synthesized RFeO 3 products. [1,18] The types of synthesis methods/conditions are varied in the literature, including solid-state reaction technique, [22] hydrothermal method, [23] microwave process, [24] mechanosynthesis, [25] sol-gel method, [15,26] solution combustion synthesis, [27] co-precipitation, [28] etc. The latter has been widely used due to its convenience and simplicity.…”

“…Regarding this method, one can vary the synthesis conditions, such as calcination temperatures, precipitating agents, and precursor mixtures. [28,29] In the present work, a variation in calcination temperatures has been investigated.…”

“…The as‐synthesized precipitates obtained by the co‐precipitation method are usually subjected to heat treatment to produce a homogeneous phase and thermostable materials. Regarding this method, one can vary the synthesis conditions, such as calcination temperatures, precipitating agents, and precursor mixtures [28,29] . In the present work, a variation in calcination temperatures has been investigated.…”