Multiferroicity and magnetoelectric coupling in half-doped manganite La0.5Ca0.5MnO3

We present experimental evidences to verify the peculiar multiferroics predicted in the half-doped manganite La0.5Ca0.5MnO3. The dielectric constant exhibits a frequency-independent peak just at the antiferromagnetic charge ordering transition temperature TCO, indicating a close correlation between the ferroelectriclike transition and charge ordering. In addition to a large magnetodielectric effect, the dynamic magnetoelectric coupling measurements provide solid evidences to an enhanced magnetoelectric coupling below TCO. Moreover, the magnetic field dependence of the coupling coefficient shows a close correlation with the magnetization hysteresis loop, which reveals that a large magnetoelectric coupling only persists in the charge ordering state.