Anomalous nanoclusters, anisotropy, and electronic nematicity in the doped manganite La1/3Ca2/3MnO3

In doped manganites, a superlattice (SL) modulation associated with charge/orbital ordering is accepted as a key component in understanding many intriguing properties. It has been reported that the SL modulation always appears on the $a$ axis of the crystals. Here, by using multiple transmission electron microscopic techniques, we observe a type of anomalous nanocluster in which the SL modulation appears on the $c$ axis of $\mathrm{L}{\mathrm{a}}_{1/3}\mathrm{C}{\mathrm{a}}_{2/3}\mathrm{Mn}{\mathrm{O}}_{3}$. By correlating the thermal evolution of the anomalous nanoclusters to other property measurements, we suggest that strain is responsible for the formation of the anomalous nanoclusters. The phase separation and phase transition scenario in $\mathrm{L}{\mathrm{a}}_{1/3}\mathrm{C}{\mathrm{a}}_{2/3}\mathrm{Mn}{\mathrm{O}}_{3}$ are also described using electronic-liquid-crystal (ELC) phases. An ELC phase diagram in $\mathrm{L}{\mathrm{a}}_{1/3}\mathrm{C}{\mathrm{a}}_{2/3}\mathrm{Mn}{\mathrm{O}}_{3}$ is constructed as a function of temperature based on our observations.