title: Large positive magnetoresistance of insulating organic crystals in the non-ohmic region.
abstract: We report a large positive magnetoresistance ratio in insulating organic crystals theta-(ET)(2)CsZn(SCN)(4) at low temperatures at which they exhibit highly nonlinear current-voltage characteristics. Despite the nonlinearity, the magnetoresistance ratio is independent of the applied voltage. The magnetoresistance ratio depends little on the magnetic field direction and is described by a simple universal function of mu(B)B/k(B)T, where mu(B) is the Bohr magneton. The positive magnetoresistance may be caused by magnetic-field-induced parallel alignment of spins of mobile and localized electrons, and a resulting blockade of electrical conduction due to the Pauli exclusion principle.
authors.affiliation: National Institute for Materials Science, Tsukuba 305-0003, Japan.
authors.forename: Yamaguchi
authors.initials: Y
authors.lastname: Takahide
authors.forename: Takako
authors.initials: T
authors.lastname: Konoike
authors.forename: Kengo
authors.initials: K
authors.lastname: Enomoto
authors.forename: Mitsuka
authors.initials: M
authors.lastname: Nishimura
authors.forename: Taichi
authors.initials: T
authors.lastname: Terashima
authors.forename: Shinya
authors.initials: S
authors.lastname: Uji
authors.forename: Hiroshi M
authors.initials: HM
authors.lastname: Yamamoto