Spin-flip transition and non-one-dimensional magnetic coupling in quasi-one-dimensional oxygen deficient Sr 6Co 5O 15-δ

High-quality single-crystal Sr6Co5O15d (d?=?1.33) was successfully synthesized with a flux method. Detailed crystalline structure was determined by single-crystal X-ray diffraction at 298?K, which revealed a quasi-one-dimensional CoO chain-like structure of this oxygen-deficient material. The magnetizations were measured in a pulsed high magnetic field up to 32?T and with a Physical Property Measurement System (PPMS). A large anisotropy and a distinct spin-flip transition were observed in the magnetization behavior. Theoretical calculation based on Botana's results suggests that interchain interaction (non-one-dimensional magnetic coupling) plays an important role in the magnetic properties of Sr6Co5O15d.