XRD and HREM Studies of Epitaxially Stabilized Hexagonal Orthoferrites RFeO₃ (R = Eu−Lu)

The formation of previously unknown hexagonal modifications of orthoferrites RFeO 3 (R = Eu−Lu) was observed on ZrO 2 (Y 2 O 3 ) (111) substrates at 900 °C. XRD and HREM studies reveal epitaxial growth of the hexagonal film. The structure of the hexagonal RFeO 3 was assigned to the ferroelectric space group P 6 3 cm . The typical structural defects in the hexagonal RMnO 3 films on ZrO 2 (Y 2 O 3 ) (111) are described. Parallel deposition on perovskite substrates results in the stable perovskite phase. The epitaxial stabilization concept successfully explains the experimental results.