Study of gadolinium substitution effects in hexagonal yttrium manganite YMnO3

Abstract

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).

Effects of Surface Polarity on the Structure and Magnetic Properties of Epitaxial h-YMnO3 Thin Films Grown on MgO Substrates

“…The E 2 symmetry modes in h-YMO/MgO (111) mainly correspond to the deformation vibration or displacement of O and Mn ions. 36,37,39,40 Thus, the Raman results suggest that there is a difference in the lattice distortion of the O−Mn−O network in both h-YMO on MgO (100) and MgO (111) substrates. We speculate that, similar to that observed in h-YMO on polar Al 2 O 3 (Al 3+ layer termination) substrate mentioned above, 15 an interface reconstruction might have occurred in h-YMO/MgO (111) system and activated the E 2 symmetry mode seen in Figure 5a.…”

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

“…We were not able to find previously published low-temperature Mössbauer data for hexagonal YFeO 3. However, for Fe in hexagonal YMnO 3 , the positions of the lines in the Mössbauer spectrum (hyperfine field of 40–44.5 T) at 12 K [ 39 ] are in rather good agreement with those of additional subspectra.…”

Molten Salt Synthesis of Micro-Sized Hexagonally Shaped REMnO3 (RE = Y, Er, Tm, Yb)

“…FT-IR spectroscopy was applied in order to investigate the structure of one of the specimens, specifically the one prepared at 1100 • C; the results are presented in Figure 3. The FT-IR can be applied to distinguish the differences between an orthorhombic and a hexagonal structure [33] for similar compounds. Compounds with an orthorhombic structure have two distinguishable peaks centered at 530 and 490 cm −1 associated with O-Mn-O bending and Re-O vibrations, respectively, while these absorption bands are missing in the samples with hexagonal structures.…”