Crystal structure, magnetic and Mössbauer studies of DyFe Mn1-O3 multiferroic manganites

The influence of iron replacement on the structural and magnetic properties of Dysprosium manganites was studied using the series of DyFexMn1-xO3 (x = 0.0, 0.1, 0.3, 0.5, 0.7, 0.9, and 1.0) compounds. All samples were fabricated by means of the modified auto-combustion sol-gel method, followed by the ball milling technique. Orthorhombic structure (Pnma space group) with high phase purity and crystallinity featured all samples, according to X-ray diffraction analysis. The temperature dependence of magnetization curves indicated antiferromagnetic (AFM) to paramagnetic (PM) transition with the increase in temperature. The Néel temperature (TN) was observed to shift to higher temperatures, whereas the spin reorientation transition temperature (TSR) reduced as Fe3+ content increased. Cusps in the zero-field-cooled (ZFC) curves were detected at low temperatures (around 4 K) as an indication of the ordering of the Dy spin. 57Fe Mӧssbauer spectra in samples with low iron content were dominated by a high spin (Fe3+) paramagnetic doublet at both 295 K and 78 K, while the distribution in the hyperfine magnetic field accounted for the appearance of the broadening magnetic peaks. High iron samples revealed a magnetic sextet with fit-resolved patterns that indicated a strong AFM coupling of Fe3+ ions. The hyperfine magnetic field (Bhf) magnitude demonstrated a linear increase with the increase in iron doping.