| Abstract
| - A new type of charge ordering stable up to T1 ≈ 500 K has been evidenced by electronmicroscopy in the Mn3+-rich perovskite Bi2/3Sr1/3MnO3. This new superstructure, based ona Imma-type subcell is characterized by a double modulation with a = 2ap, b = 4ap, c =ap. X-ray powder diffraction evidences a second structural transition at T2 ≈ 580 K andsuggests a displacive modulation of the oxygen atoms below T2. These results are interpretedas the correlated coexistence of charge-orbital ordering and modulated displacive orderingof oxygen atoms, in the form of double Mn stripes, below 500 K.
- A new type of charge ordering, characterized by a double modulation with a = 2ap, b = 4ap, c = apand stable up to T1 ≈ 500 K, has been evidenced by transmission electron microscopy in the perovskite Bi2/3Sr1/3MnO3. A second structural transition appears at T2 ≈ 580 K. These results are interpreted as the correlated coexistence of charge-orbital ordering and modulated displacive ordering of oxygen atoms, in the form of double Mn stripes, below 500 K.
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