Structural and ferroelectric properties of orthogonal crystalline in Fe-doped HoMnO3 synthesized at normal pressure

A typical multiferroic manganese oxide of HoMnO3 was partially substituted by Fe at Mn site. Orthogonal crystalline phase of HoMn1−xFexO3 was synthesized at normal pressure. This finding has changed the conventional method of synthesizing orthogonal crystalline phase of rare-earth manganese oxides under high-temperature and high-pressure. The doping of iron ions suppresses the formation of hexagonal phase as revealed from X-ray diffraction, Morphology analysis, Raman spectrum and X-ray photoelectron spectroscopy. The doping of Fe3+ into HoMnO3 causes changes in the space group of the sample and ferroelectricity at room temperature. There are two phases with a ferroelectric space group of $${P6}_{3}cm$$ and a paraelectric one of Pnma coexisted in Ho $${\text{Mn}}_{1-x}{Fe}_{x}{O}_{3}$$ polycrystalline with x 0.15, the phase with $${P6}_{3}cm$$ space group disappears, and samples have only one crystalline phase Pnma. We found that the sample remained ferroelectricity at room temperature in the process of changing the doping concentration. The ferroelectric property disappears until it completely changed to the orthogonal phase. The synthesis of orthogonal HoMnO3 at normal pressure has not been previously reported and potentially open up abroad research and application prospects.