Short-range charge-ordering correlated elastic anomalies in La2/3Sr1/3FeO3

The longitudinal and transverse ultrasonic velocities in single-phase polycrystalline La2/3Sr1/3FeO3 have been measured by a conventional pulse-echo-overlap technique at a frequency of 10 MHz. Dramatic anomalies in sound velocities for both longitudinal and transverse modes were observed near 214 K. These abnormal ultrasonic features can be fitted by the mean-field theory, which confirms the presence of the Jahn–Teller effect originating from the Fe4+. However, no obvious anomalies in magnetic and electric properties were found in this temperature range. These results give new evidence for the short-range charge ordering state.