Low-temperature thermal conductivity of BaFe2As2: Parent compound of iron-arsenide superconductors

الأصل · EN

We report low-temperature thermal conductivity down to 40 mK of the antiferromagnet BaFe₂As₂, which is the parent compound of recently discovered iron-based superconductors. In the investigated temperature range below 4 K, the thermal conductivity κ is well described by the expression κ = aT + bT².²². We attribute the ``aT''-term to an electronic contribution which is found to satisfy the Wiedemann-Franz law in the T → 0 K limit, and the remaining thermal conductivity, T².²², is attributed to phonon conductivity. A small influence on thermal conductivity by magnetic fields up to 8 T is well accounted by the observed magnetoresistance. The result is consistent with a fully gapped magnon spectrum, inferred previously from inelastic neutron scattering measurements.