title: Commensurate-incommensurate crossover of charge stripe in La2-xSrxNiO4 (x approximately 1/3).
abstract: The temperature (T) dependence of the charge-stripe order in La2-xSrxNiO4 has been investigated in the vicinity of x approximately 1/3 by synchrotron radiation x-ray diffraction measurements. With decreasing T, a prominent commensurate-incommensurate (C-IC) crossover is observed in the x<1/3 region, while for the x>1/3 region the IC order is dominant over the whole T range. Such a C-IC crossover is interpreted as the entropy-driven self-doping of the charge stripes, and its x dependence indicates the clear electron-hole asymmetry with the x=1/3 compound as the Mott insulator.
authors.affiliation: Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ishizaka
authors.forename: T
authors.initials: T
authors.lastname: Arima
authors.forename: Y
authors.initials: Y
authors.lastname: Murakami
authors.forename: R
authors.initials: R
authors.lastname: Kajimoto
authors.forename: H
authors.initials: H
authors.lastname: Yoshizawa
authors.forename: N
authors.initials: N
authors.lastname: Nagaosa
authors.forename: Y
authors.initials: Y
authors.lastname: Tokura