Phase relationship of the TbO1.81–Mn3O4–Fe2O3 system synthesized at 1200 °C

Highlights: ► We report the phase relationship of the TbO1.81–Mn3O4–Fe2O3 system synthesized at 1200 °C. ► The solid solution (Tb1−xMnyFez)(FewMn1−w)O3 is isostructural to TbMnO3. ► The boundary of the solid solution (Tb1−xMnyFez)(FewMn1−w)O3 is carefully determined. ► The neutron diffraction data indicates that Mn of Fe can be doped into the Tb site of TbMnO3. -- Abstract: The phase relationship of the TbO1.81–Mn3O4–Fe2O3 pseudo-ternary system synthesized at 1200 °C was determined using X-ray and neutron diffraction method. Four solid solutions, Mn3−3xFe3xO4 (0.00 ⩽ x ⩽ 0.278), Mn3−3xFe3xO4 (0.291 ⩽ x ⩽ 0.667), Mn2−2xFe2xO3 (0.89 ⩽ x ⩽ 1.00), and (Tb1−yMnzFex)(FewMn1−w)O3 (1−y + x + z ⩽ 1, 0.00 ⩽ w ⩽ 1.00) were found along with six two-phase regions and three three-phase regions. The boundaries were determined by several different methods such as phase disappearing, the Vigard's law, and the lever rule