Specific-heat evidence of strong electron correlations and thermoelectric properties of the ferromagnetic perovskite SrCoO_(3-δ)

摘要

A dense pellet of the polycrystalline SrCoO_(3-δ) (0 ≤ δ < 0.2) was obtained by a high-pressure method, and electronic transport properties of the stoichiometric perovskite were measured. A large electronic specific-heat coefficient was found [45.7(2) mJ mol~(-1) K~(-2)], indicating a moderate degree of electrons correlation: the mass enhancement factor was 6.1, which is higher than that for the Ad ferromagnetic perovskite SrRuO_3 (4.4). The thermoelectric properties of SrCoO_3 were found to be sensitive to band filling, in contrast to those of SrRuO_3.