Phonon thermal conductivity in single layered manganites

We present measurements of the thermal transport in single crystals of single-layered manganites La 1 - x Sr 1 + x MnO 4 with 0 ⩽ x ⩽ 0.5 . The data reveal a strong but non-monotonic suppression of the phonon thermal conductivity κ ph upon hole-doping. The suppression of κ ph originates from scattering of phonons by polaronic holes. The suppression is particularly strong when charge and orbital degrees of freedom are disordered and rather weak in the case of long-range charge and orbital ordering. Moreover, slight anomalies are found in the vicinity of antiferromagnetic phase transitions, probably due to scattering of phonons by magnetic fluctuations.