We report on an electronic structural study of BaFe1.7Co 0.3As2 in heavily electron doped regime of the FeAs-based superconductors. Three hole bands around the zone center are clearly observed and two of them reach the Fermi level (EF) forming two hole pockets. Top of the lowest hole band is located at ∼30 meV below EF showing that it undergoes a pocket-vanishing type Lifshitz transition by electron doping. Around the zone corner, two electron pockets are clearly observed, and the smaller electron pocket is apparently nested with the larger hole pocket at the zone center.
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