Hydrothermal synthesis of two perovskite rare-earth manganites, HoMnO3 and DyMnO3

Two perovskite rare-earth manganites RMnO3 (R=Ho, Dy) were synthesized from the hydrothermal redox reactions of KMnO4 and MnCl2 at 250 °C and characterized by means of X-ray diffraction, scanning electron microscopy and SQUID. They are orthorhombic, whereas the hexagonal phases, which were competitive strongly with the orthorhombic phases in solid-state reactions, are avoided in the hydrothermal systems. The pure metastable manganites may serve as a model for understanding the magnetisms of Jahn–Teller distortion and charge ordering. This new synthetic approach leaves many rooms for new doped or undoped RMnO3 compounds.