Observation of resistance switching between insulating and metallic states in nano-crystalline La0.65Ca0.35MnO3 film

The magnetic and transport properties of a 20-nm-scale twinned La0.65Ca0.35MnO3 film have been investigated in a temperature range of 77-300 K. The coexistence of ferromagnetic metallic (FM) and charge-ordered insulating (COI) phases is suggested based on analysis of resistance temperature and current dependencies at low temperatures. It is shown that thermocycling leads to formation of a non-equilibrium state in the ensemble of the charge-ordered domains and to appearance of a giant (up to 100%) resistance switching between MF and COI states. The experimental results are discussed from the viewpoint of the phase separation phenomenon.