Structural, dielectric, and magnetic properties of epitaxially grown BaFeO3 thin films on (100) SrTiO3 single-crystal substrates

We have prepared single-crystalline films of BaFeO3, which may contain high valent Fe4+ ions, on (100) SrTiO3 substrates by pulsed laser-beam deposition. The reflection high-energy electron diffraction patterns for the films apparently show a C4 symmetry operation, suggesting that the sample had a pseudocubic perovskite structure rather than hexagonal unit cell. The films were found to be highly insulating, and showed a high value of dielectric constant of e=59. At 300 K, the magnetization loop of the film apparently shows hysteresis, as well as small remanent magnetization. These characteristics are totally different from those of bulk BaFeO3.