Abstract
Resistive properties of point contacts in normal-metal-manganite heterojunctions have been investigated on the base of La0.7Sr0.3MnO3, La0.8Sr0.2MnO3, La0.8Ca0.2MnO3 single crystals. At considerable current levels the current-voltage characteristics of point contacts exhibit features in the form of resistance peaks at lower temperatures. Colossal magnetoresistance also considerably increases under transport current in the investigated heterojunctions. It has been assumed that the observed current switching effects are due to phase separation of manganites under the electric current.