title: Magnetic anisotropy of the antiferroquadrupole phase in Ce0.50La0.50B6.
abstract: Magnetic phase diagrams for antiferroquadrupole (AFQ) phase II and antiferromagnetic (AFM) phase III in Ce0.50La0.50B6 with a Gamma(8) ground state have been investigated by ultrasonic measurements. The hybrid magnet (Gama) in the National Institute for Materials Science was employed for high-field measurements up to 30 T and a 3He-4He dilution refrigerator was used for low-temperature experiments down to 20 mK. The phase boundary from paramagnetic phase I to AFQ phase II under [001] magnetic fields closes at H(I-II) approximately 29 T, while the boundary is still open under fields along the [110] and [111] directions even up to 30 T. This anisotropic character of phase II in fields is consistent with the theoretical calculation based on the O(xy)-type AFQ ordering. We also found that AFM phase III reduces considerably in fields turning from the [001] to [110] and [111] directions.
authors.affiliation: Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Akatsu
authors.forename: Terutaka
authors.initials: T
authors.lastname: Goto
authors.forename: Osamu
authors.initials: O
authors.lastname: Suzuki
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Nemoto
authors.forename: Shintaro
authors.initials: S
authors.lastname: Nakamura
authors.forename: Satoru
authors.initials: S
authors.lastname: Kunii
authors.forename: Giyuu
authors.initials: G
authors.lastname: Kido