title: Metamagnetic transition in Na 0.85 CoO2 single crystals.
abstract: We report the magnetization, specific heat, and transport measurements of a high quality Na(0.85)CoO2 single crystal in applied magnetic fields up to 14 T. At high temperatures, the system is in a paramagnetic phase. It undergoes a magnetic phase transition below approximately 20 K. For the field H||c, the measurement data of magnetization, specific heat, and magnetoresistance reveal a metamagnetic transition from an antiferromagnetic state to a quasiferromagnetic state at about 8 T at low temperatures. However, no transition is observed in the magnetization measurements up to 14 T for H perpendicular c. The low temperature magnetic phase diagram of Na(0.85)CoO2 is determined.
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China.
authors.forename: J L
authors.initials: JL
authors.lastname: Luo
authors.forename: N L
authors.initials: NL
authors.lastname: Wang
authors.forename: G T
authors.initials: GT
authors.lastname: Liu
authors.forename: D
authors.initials: D
authors.lastname: Wu
authors.forename: X N
authors.initials: XN
authors.lastname: Jing
authors.forename: F
authors.initials: F
authors.lastname: Hu
authors.forename: T
authors.initials: T
authors.lastname: Xiang