Chemical solution deposition of la-substituted BiFe0.5Sc0.5O3 perovskite thin films on different substrates

In the present work, polycrystalline Bi0.67La0.33Fe0.5Sc0.5O3 thin films were synthesized using a simple and cost‐effective chemical solution deposition process employing the spin coating tech‐ nique. In order to check the feasibility of the fabrication of thin films on various types of substrates, the films were deposited on Pt‐coated silicon, silicon, sapphire, corundum, fused silica and glass. Based on the results of thermogravimetric analysis of precursor and thermal stability study, it was determined that the optimal annealing temperature for the formation of perovskite structure is 600 °C. It was observed that the relative intensity of the pseudocubic peaks (001)p and (011)p in the XRD patterns is influenced by the nature of substrates, suggesting that the formed crystallites have some preferred orientation. Roughness of the films was determined to be dependent on the nature of the substrate.publishe

Molten salt synthesis of micro-sized hexagonally shaped REMnO3 (RE = Y, Er, Tm, Yb)

Yttrium manganite (YMnO3) is a compound belonging to the hexagonal rare earth manganites family, which demonstrates multiferroic properties. This material can be prepared by several synthetic approaches, with the most common one being the solid-state synthesis. In this work, we show a possibility of preparing this material via molten salt synthesis using the NaCl-KCl mixture as the reaction medium and yttrium and manganese nitrates as the starting materials. We demonstrate that, by varying the reaction temperature and the nitrates-to-chlorides ratio, it is feasible to synthesize hexagonally shaped particles of microscopic dimensions. A similar synthesis procedure can be successfully applied for the preparation of other hexagonal manganites—ErMnO3, TmMnO3, and YbMnO3

Sol-Gel Synthesis and Characterization of Yttrium-Doped MgFe2O4 Spinel

In this study, an environmentally friendly sol-gel synthetic approach was used for the preparation of yttrium-doped MgFe2O4. Two series of compounds with different iron content were synthesized and A-site substitution effects were investigated. In the first series, the iron content was fixed and the charge balance was suggested to be compensated by a partial reduction of Fe3+ to Fe2+ or formation of interstitial O2− ions. For the second series of samples, the iron content was reduced in accordance with the substitution level to compensate for the excess of positive charge, which accumulates due to replacing divalent Mg2+ with trivalent Y3+ ions. Structural, morphological and magnetic properties were inspected. It was observed that single-phase compounds can only form when the substitution level reaches 20 mol% of Y3+ ions and iron content is reduced. The coercivity as well as saturation magnetization decreased with the increase in yttrium content. Mössbauer spectroscopy was used to investigate the iron content in both tetrahedral and octahedral positions

Study of gadolinium substitution effects in hexagonal yttrium manganite YMnO3

In the present work, gadolinium substitution effects on the properties of yttrium manganite YxGd1−xMn0.97Fe0.03O3 (x from 0 to 1 with a step of 0.2) synthesized by an aqueous sol–gel method have been investigated. Partial substitution of Mn3+ by 57Fe3+ in the manganite was also performed in order to investigate deeper the structural properties of synthesized compounds applying Mössbauer spectroscopy. It was demonstrated that substitution of Y3+ by Gd3+ ions leads to the changes of structural, magnetic and morphological properties of investigated system. The crystal structure gradually transformed from hexagonal to orthorhombic with an increase of Gd3+ content in the crystal lattice. The mixed phase was obtained when x = 0.6, whereas other compounds were determined to be monophasic. Magnetization measurements revealed paramagnetic behavior of all specimens, however magnetization values were found to be dependent on chemical composition of the samples. Solid solutions with orthorhombic structure revealed higher magnetization values compared to those of hexagonal samples. The highest magnetization was observed for pure GdMn0.97Fe0.03O3. Structural properties were investigated by powder X-ray diffraction, Mössbauer, FTIR and Raman spectroscopies. Morphological features of the synthesized specimens were studied by scanning electron microscopy (SEM)

The synthesis and characterization of sol-gel-derived SrTiO3-BiMnO3 solid solutions

In this study, the aqueous sol-gel method was employed for the synthesis of (1−x)SrTiO3-xBiMnO3solid solutions. Powder X-ray diffraction analysis confirmed the formation of single-phase perovskites with a cubic structure up to x=0.3.A further increase of the BiMnO3content led to the formation of a negligible amount of neighboring Mn3O4 impurity,along with the major perovskite phase.Infrared(FT-IR) analysis of the synthesized specimens showed gradual spectral change associated with the superposition effect of Mn-O and Ti-O bond lengths.By introducing BiMnO3 into the SrTiO3 crystal structure,the size of the grains increased drastically, which was confirmed by means of scanning electron microscopy. Magnetization studies revealed that all solid solutions containing the BiMnO3 component can be characterized as paramagnetic materials. It was observed that magnetization values clearly correlate with the chemical composition of powders, and the gradual increase of the BiMnO3 content resulted in noticeably higher magnetization values

Lanthanum and manganese Co-doping effects on structural, morphological, and magnetic properties of sol-gel derived BiFeO3

In this work, lanthanum and manganese co-substitution effects on different properties of bismuth ferrite solid solutions Bi1-xLaxFe0.85Mn0.15O3 (x from 0 to 1) prepared by a sol-gel synthetic approach have been investigated. It was observed that the structural, morphological, and magnetic properties of obtained specimens are influenced by the amount of introduced La3+ ions. Surprisingly, only the compound with a composition of BiFe0.85Mn0.15O3 was not monophasic, and the presence of neighboring phases was determined from X-ray diffraction analysis and Mössbauer measurements. Structural transitions from orthorhombic to cubic and back to orthorhombic were also observed depending on the La3+ amount. Antiferromagnetic behaviour was observed for all of the samples, with the highest magnetisation values for Bi0.5La0.5Fe0.85Mn0.15O3. Additionally, structural attributes and morphological features were evaluated by Raman spectroscopy and scanning electron microscopy (SEM), respectively