title: First-order metal-insulator transitions in manganites: are they universal?
abstract: Conductivity data for La(2-2x)Sr(1+2xMn2O7 (x = 0.6) show a first-order transition from an orbital- or charge-ordered insulator to a metal as the temperature falls below approximately 160 K. The change in conductivity is 100 times larger than that seen previously in any single-phase manganite in zero field. The metallic low-temperature state is similar to x = 0.58, but x = 0.58 shows no evidence of orbital or charge order. This result supports a conclusion that strongly coupled magnetic-conductive transitions are first order.
authors.affiliation: Chinese Academy of Sciences, Beijing, China.
authors.forename: Qing' An
authors.initials: QA
authors.lastname: Li
authors.forename: K E
authors.initials: KE
authors.lastname: Gray
authors.forename: S Nyborg
authors.initials: SN
authors.lastname: Ancona
authors.forename: H
authors.initials: H
authors.lastname: Zheng
authors.forename: S
authors.initials: S
authors.lastname: Rosenkranz
authors.forename: R
authors.initials: R
authors.lastname: Osborn
authors.forename: J F
authors.initials: JF
authors.lastname: Mitchell