We have performed an x-ray angle-resolved photoemission spectroscopy (ARPES) on Ca1-xLaxB6 (x=0.005) to study the band structure relevant to the anomalous high-temperature ferromagnetism. The obtained band structure shows a good agreement with the GW band calculation as well as the previous ARPES results with ultraviolet light. This indicates that CaB6 is not an excitonic insulator, but is intrinsically a semiconductor with a 1-eV gap at the X point.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2004 Aug|