title: Magnetic phase separation in La1-xSrxCoO3 by 59Co nuclear magnetic resonance.
abstract: 59Co NMR measurements on La1-xSrxCoO3 reported here establish unequivocally, for the first time, the coexistence of ferromagnetic regions, spin-glass regions, and hole-poor low spin regions at all x values from 0.1 to 0.5. A zero external field NMR spectrum, which is assigned to the ferromagnetic regions, has a spectral shape that is nearly x independent at 1.9 K, as are the relaxation times, T1 and T2. The integrated spectral area increases rapidly with x up to x = 0.2 and then decreases slightly for larger x. In a field of 9.97 T, a narrow NMR line is observed at 102 MHz, identical to that found in x = 0 samples in previous work. The integrated intensity of this spectrum decreases rapidly with increasing x, and is ascribed to hole-poor low spin regions. Beneath this spectrum, a third broad line, with a peak at 100 MHz, is assigned to a spin- or cluster-glass-like phase.
authors.affiliation: National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA.
authors.forename: P L
authors.initials: PL
authors.lastname: Kuhns
authors.forename: M J R
authors.initials: MJ
authors.lastname: Hoch
authors.forename: W G
authors.initials: WG
authors.lastname: Moulton
authors.forename: A P
authors.initials: AP
authors.lastname: Reyes
authors.forename: J
authors.initials: J
authors.lastname: Wu
authors.forename: C
authors.initials: C
authors.lastname: Leighton