Disappearance of peculiarly large atomic displacement in the high-temperature phase of magnetite with substitution of Fe2+ by Ni2+and Mn2+

Structures of Fe2.992O4 (magnetite), Fe3–x–yMnx□yO4 (x ≤ 0.980) and Fe3–x–yNix□yO4 (x ≤ 0.513, □ denotes point defects) are examined at room temperature. The observed disappearance of peculiarly large mean-square displacement at the B site along the 3 axis in [111] is interpreted as a disappearance of phonons interact with electrons in the high-temperature phase of magnetite.