High-pressure synthesis of the layered iron oxyselenide BaFe2Se2O with strong magnetic anisotropy

作者：Takeiri, Fumitaka; Matsumoto, Yuki; Yamamoto, Takafumi; Hayashi, Naoaki; Li, Zhi; Tohyama, Takami; Tassel, Cedric; Ritter, Clemens; Narumi, Yasuo; Hagiwara, Masayuki; Kageyama, Hiroshi^*

来源：Physical Review B, 2016, 94(18): 184426.

DOI：10.1103/PhysRevB.94.184426

• SUPERCONDUCTIVITY
• 2-COORDINATE
• TEMPERATURE
• TRANSITION
• COMPLEX
• PEROVSKITE

Using a high-pressure reaction, we successfully synthesized BaFe2Se2O with a uniform stack of [Fe2Se2O] layers. Magnetic susceptibility, heat capacity, Mossbauer spectroscopy, and neutron-diffraction measurements revealed that BaFe2Se2O undergoes antiferromagnetic order at 106 K with a 2-k spin structure where each Fe moment points to a neighboring oxide anion. The same spin structure has been observed in the related iron oxyselenides but with a staggered stack of [Fe(2)Ch(2)O] (where Ch represents chalcogen) layers (Ch = S, Se). We propose that the strong uniaxial anisotropy inferred from the 2-k structure originates from spin-orbit coupling (SOC) induced by a trans-FeO2Se4 octahedron, which provides a quasilinear coordination environment as often found in single molecule magnetic complexes. A first-principles calculation with inclusion of SOC supports the stabilization of the 2-k spin structure, giving an unquenched orbital momentum of 0.1 mu(B)/Fe. The present paper provides an idea of how to design magnetic lattices of uniaxial anisotropy using oxychalcogenides and more generally mixed-anion compounds.

• 出版日期2016-11-21
• 单位合肥工业大学