Anomalous phase separation in La0.225Pr0.4Ca0.375MnO3: consequence of temperature and magnetic-field cycles

The evolutions of electronic phase separation in manganites La0.225Pr0.4Ca0.375MnO3 are studied by the specific temperature and magnetic-field cycling experiments. It is found that the electronic phase separation state at low temperature can be tuned substantially by temperature and/or magnetic-field cycles. Surprisingly, the initial more ferromagnetic metallic (FMM) nuclei can impede the growth of these nuclei during the cooling process. It implies that there must coexist more than two phases which take part in the complex first-order phase transitions, and the charge-disordered insulating phase is possible, one of the parent phases transiting into the FMM phase at low temperature. In addition, the accommodation strain is suggested to control the nucleation and growth of FMM domains.