Spin wave anomalies and phonons at low temperature in La0.875Sr0.125Mno3

In the diagram of La 1− x Sr x MnO 3 the compound with x =0.125, exhibits, below T c =181 K, a ferromagnetic phase. At T O′O″ =159 K, a magneto-structural transition occurs with amazing properties. New superstructure Bragg peaks appear. At related q -values, the spin wave energies split and lock at the values of phonon modes. This suggests a complex ground state with mixed magneto-vibrational excitations.