We have studied the chemical potential shift in La2-xSrxNiO4 and the charge ordering transition in La1.67Sr0.33NiO4 by photoemission spectroscopy. The result shows a large (∼1 eV/hole) downward shift of the chemical potential with hole doping in the high-doping regime (δ≳0.33) while the shift is suppressed in the low-doping regime (δ≲0.33). This suppression is attributed to a segregation of doped holes on a microscopic scale when the hole concentration is lower than δ≃1/3. In the δ=1/3 sample, the photoemission intensity at the chemical potential vanishes below the charge ordering transition temperature TCO=240 K.
|Number of pages||4|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2000|
ASJC Scopus subject areas
- Condensed Matter Physics