Evidence for the charge-ordered state and phase separation at room temperature in half-doped La0.5Ca0.5MnO3 films

The microstructure and the magnetotransport properties of La0.5Ca0.5MnO3 films, prepared by rf magnetron sputtering on a LaAlO3 substrate, have been investigated. The electron-diffraction and the high-resolution electron-microscopy studies reveal the coexistence at room temperature of double-period modulated (charge-ordered) and unmodulated (charge-disordered) phases. It is suggested that the high-temperature fragmentation of film results in the magnetic-phase-separated state at low temperatures.