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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). [ABSTRACT FROM AUTHOR]

In this study, the BixLa1−xMnO3+δ solid solutions (x from 0 to 0.65) were synthesized using sol–gel combustion method with citric acid as a fuel and complexing agent. It was shown that changes in chemical composition of the materials lead to the evolution of crystal structure, morphology, and magnetic properties. The thermal behavior of precursor gel was investigated by thermogravimetric and differential scanning calorimetry (TG-DSC) measurements. X-ray diffraction (XRD) analysis demonstrated that all samples were monophasic. The Rietveld analysis showed that the structure can be indexed by trigonal or cubic unit cell depending on Bi3+ content. Scanning electron microscopy (SEM) was used to evaluate morphological features of the synthesized materials and revealed that Bi3+ ions significantly promote growth of the grains. The sol–gel-derived BixLa1−xMnO3+δ specimens were also characterized by FT-IR spectroscopy and magnetization measurements, which showed a clear correlation between magnetic properties and crystal structure of the materials. Highlights: BixLa1–xMnO3+δ solid solutions (x from 0 to 0.65) were synthesized by the sol–gel combustion method. The suggested synthetic approach does not require addition of external solvent. Structural, morphological and magnetic properties depend on the chemical composition of compounds. [ABSTRACT FROM AUTHOR]