title: High-field magnetization of a two-dimensional spin frustration system, Ni(5)(TeO(3))(4)X(2) (X =  Br, Cl).
abstract: The high-field magnetization, M(H), of Ni(5)(TeO(3))(4)X(2) (X =  Br, Cl) was measured by using a pulse magnet. These compounds have a two-dimensional crystal structure and a distorted Kagome spin frustrated system which is built from the Ni(2+) ions (S = 1). The Néel transition temperatures are T(N)∼28 and 23 K for X =  Br and Cl, respectively. When T<T(N), we observe step-like transitions, at H(c)∼11 and 10 T for X =  Br and Cl, respectively. On the other hand, for T>T(N), the field-dependent magnetization curves behave like a monotonically increasing straight line up to 55 T. The H(c) value is close to those obtained in previous spin resonance studies in which a model of a spin-flop scenario was proposed to explain the field-dependent resonance spectra. With the earlier model a further transition at around 23 T was predicted; however, our observations did not show any plateau behaviors, saturation or other anomalies up to 55 T, suggesting that the further transition possibly exists in a much higher field region.
authors.affiliation: Institute for Solid State Physics, University of Tokyo, Japan.
authors.forename: J L
authors.initials: JL
authors.lastname: Her
authors.forename: Y H
authors.initials: YH
authors.lastname: Matsuda
authors.forename: K
authors.initials: K
authors.lastname: Suga
authors.forename: K
authors.initials: K
authors.lastname: Kindo
authors.forename: S
authors.initials: S
authors.lastname: Takeyama
authors.forename: H
authors.initials: H
authors.lastname: Berger
authors.forename: H D
authors.initials: HD
authors.lastname: Yang