Transverse ultrasonic anomaly in La1/3Sr2/3MnO3

The charge ordering (CO) transition in polycrystalline La1/3Sr2/3MnO3 has been studied by measuring the resistivity, magnetization and transverse ultrasonic velocity. At about 235K, a conspicuous increase in resistivity was observed, while the magnetization shows a cusp structure, corresponding to an antiferromagnetic charge ordering transition. Around this transition temperature, dramatic anomaly in transverse sound velocity was observed. The simultaneous occurrence of electron, magnon and phonon anomalous features implies strong spin-phonon coupling and electron-phonon in La1/3Sr2/3MnO3. The analysis suggests that the spin-phonon interaction is due to single-ion magnetostriction, and electron-phonon coupling originates from the Jahn-Teller effect of Mn3+.