Commensurate-incommensurate crossover of charge stripe in La2-xSrxNiO4 (x approximately 1/3).
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.
Ishizaka
K
K
Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
Arima
T
T
Murakami
Y
Y
Kajimoto
R
R
Yoshizawa
H
H
Nagaosa
N
N
Tokura
Y
Y