Strained Structure in Ho0.5Sr0.5MnO3

The Ho0.5Sr0.5MnO3 perovskite, synthesized in air, has been studied by combining neutron powder and electron diffraction techniques. The Pnma-type structure exhibits a strong tilting of the MnO6 octahedra. This octahedra tilting and microtwinning involve a complex strained structure. No structural transition is observed down to 1.4 K, but short-range A-type antiferromagnetism running over only a few perovskite subcells is evidenced below ~90 K. The different behavior of this perovskite compared to other Ln0.5Sr0.5MnO3 perovskites is discussed in terms of A-site cationic mismatch.