title: High-Pressure Synthesis, Crystal Structure, and Magnetic Properties of Sr2MnO3F: A New Member of Layered Perovskite Oxyfluorides.
abstract: We have successfully synthesized Sr2MnO3F, a new layered perovskite oxyfluoride with a n = 1 Ruddlesden-Popper-type structure using a high-pressure, high-temperature method. Structural refinements against synchrotron X-ray diffraction data collected from manganese oxyfluoride demonstrated that it crystallizes in a tetragonal cell with the space group I4/mmm, in which the Mn cation is located at the octahedral center position. This is in stark contrast to the related oxyhalides that have square-pyramidal coordination such as Sr2MO3X (M = Fe, Co, Ni; X = F, Cl) and Sr2MnO3Cl. There was no evidence of O/F site order, but close inspection of the anion environment centered at the Mn cation on the basis of bond-valence-sum calculation suggested preferential occupation of the apical sites by the F ion with one oxide ion in a random manner. Magnetic susceptibility and heat capacity measurements revealed an antiferromagnetic ordering at 133 K (=TN), which is much higher than that of the chloride analogue with corrugated MnO2 planes (TN = 80 K).
authors.affiliation: Superconducting Properties Unit, National Institute for Materials Science (NIMS) , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.|Graduate School of Chemical Sciences and Engineering, Hokkaido University , North 10 West 8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Su
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Tsujimoto
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Matsushita
authors.affiliation: Superconducting Properties Unit, National Institute for Materials Science (NIMS) , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.|Graduate School of Chemical Sciences and Engineering, Hokkaido University , North 10 West 8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.
authors.forename: Yahua
authors.initials: Y
authors.lastname: Yuan
authors.affiliation: Superconducting Properties Unit, National Institute for Materials Science (NIMS) , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.|Graduate School of Chemical Sciences and Engineering, Hokkaido University , North 10 West 8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: He
authors.affiliation: Superconducting Properties Unit, National Institute for Materials Science (NIMS) , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.|Graduate School of Chemical Sciences and Engineering, Hokkaido University , North 10 West 8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Yamaura