Electron density of states at the charge-density-wave phase in the blue bronze K0.3MoO3

We have investigated the differential conductance of point contact that is formed by Pt wire and (2¯ 01) plane of the quasi-one-dimensional blue bronze K0.3MoO3 down to T∼40K. Below T∼70K, that temperature is well lower than the charge-density wave (CDW) transition temperature TCDW=180K, we found the double gaps like structure that becomes definite with decreasing temperature. From the singularities of the structure, the energy gaps are estimated as 2Δ1∼112meV and 2Δ2∼60meV, respectively. It is suggested that the structure is affected to the imperfect nesting of the Fermi surfaces. Both the two- and three-dimensionality would play important role in the electronic system of K0.3MoO3.