Low-temperature specific heat of La0.67Ba0.33MnO3 and La0.8Ca0.2MnO3

Abstract
We report measurements of the specific heat of La0.67 Ba0.33MnO3 and La0.8 Ca0.2MnO3 for temperatures 2<T<15 K. These materials are ferromagnetic metallic oxides which exhibit colossal magnetoresistance. We find that above 3 K the specific heat has terms proportional to T and T3, but a T32 term, as might be expected from the excitation of ferromagnetic spin waves, cannot be resolved outside of the precision of the data. The cubic term gives Debye temperatures of 400±17 K, and the linear term gives electron densities of states which are enhanced over band-structure estimates.