title: Spin freezing and magnetic inhomogeneities in bilayer manganites.
abstract: We have performed a muon spin rotation study on polycrystalline samples of electron-doped layered manganites, La2-2xSr1+2xMn2O7 (0.4< or =x<1), in order to investigate the local magnetic structure and spin dynamics. Our results provide evidence for phase separation into A-type antiferromagnetic and charge-ordered phases for x=0.52 and spin freezing at low temperatures (T<100 K) for 0.52< or =x<0.75. A new phase diagram which includes this spin-freezing region is proposed.
authors.affiliation: Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom.
authors.forename: A I
authors.initials: AI
authors.lastname: Coldea
authors.forename: S J
authors.initials: SJ
authors.lastname: Blundell
authors.forename: C A
authors.initials: CA
authors.lastname: Steer
authors.forename: J F
authors.initials: JF
authors.lastname: Mitchell
authors.forename: F L
authors.initials: FL
authors.lastname: Pratt