title: Random potential effect near the bicritical region in perovskite manganites as revealed by comparison with the ordered perovskite analogs.
abstract: The orbital-charge-spin ordering phase diagram for half-doped perovskites Ln(1/2)Ba(1/2)MnO3 (Ln = rare earth) with ordered Ln/Ba cations has been investigated comparatively with that of the Ln/Ba solid-solution analogs. A large modification of the phase diagram is observed upon the A-site disordering near the original bicritical point between the charge-orbital ordering and ferromagnetic metallic phases. The random potential by quenched disorder inherent in the A-site solid solution is found to suppress the respective long-range orders and gives rise to the colossal magnetoresistive state.
authors.affiliation: Correlated Electron Research Center, Advanced Industrial Science and Technology, Tsukuba 305-8562, Japan.
authors.forename: D
authors.initials: D
authors.lastname: Akahoshi
authors.forename: M
authors.initials: M
authors.lastname: Uchida
authors.forename: Y
authors.initials: Y
authors.lastname: Tomioka
authors.forename: T
authors.initials: T
authors.lastname: Arima
authors.forename: Y
authors.initials: Y
authors.lastname: Matsui
authors.forename: Y
authors.initials: Y
authors.lastname: Tokura