The cobaltates have demonstrated a wide variety complex behavior. The Na rich region of the phase diagram displays various degrees of anomalous behavior, such as Curie-Weiss behavior near a band insulatorcite{Foo:2004}, charge disproportionationcite{Mukhamedshin:2005}, and non-Fermi-liquid behavior in the resistivitycite{Foo:2004}. Alternatively, the Na poor region of the phase diagram appears to be a Fermi-liquid. The magnetic susceptibility displays Pauli behavior, the resistivity is roughly quadratic at low temperaturescite{Foo:2004}, and the system appears to be homogeneouscite{Mukhamedshin:2005}. Therefore, the Na poor region of the phase diagram seems like a natural starting point to attempt to explain the ARPES experiments and heat capacity measurements from a quantitative standpoint.
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