title: Magnetic-field induced transition to the 1/2 magnetization plateau state in the geometrically frustrated magnet CdCr2O4.
abstract: The magnetization of the geometrically frustrated spinel CdCr2O4 was measured in pulsed fields of up to 47 T. We found a metamagnetic transition to a very wide magnetization plateau state with one half of the full moment of S=3/2 Cr3+ at 28 T, independent of the field direction. This is the first observation of magnetization plateau state realized in Heisenberg pyrochlore magnet. The plateau state can be ascribed to a collinear spin configuration with three-up and one-down spins out of four spins of each Cr tetrahedron. A large magnetostriction is observed at the transition in spite of the negligible spin-orbit couplings. We argue that spin frustration plays a vital role in this large spin-lattice coupling.
authors.affiliation: RIKEN (The Institute of Physical and Chemical Research), 2-1, Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ueda
authors.forename: Hiroko Aruga
authors.initials: HA
authors.lastname: Katori
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mitamura
authors.forename: Tsuneaki
authors.initials: T
authors.lastname: Goto
authors.forename: Hidenori
authors.initials: H
authors.lastname: Takagi