| Abstract [eng] |
In this dissertation application of the lanthanum manganite films and their heterostructures for fabrication of new spintronic devices is discussed. The main subjects of this work are the junctions between lanthanum manganite oxide thin films doped by divalent (Ca, Ba, Sr) and tetravalent (Ce) ions as well heterojunctions formed between lanthanum manganites and n-type SrTiO3<Nb> (STON) or n - Si substrates. The influence of doping and substrate influence on crystalline quality of manganite film structures, interface roughness as well as their electrical and magnetic properties has been estimated in this dissertation. After performing complex investigations it has been determined that tetravalent Ce ion doped lanthanum manganite films have not the electron but hole-type conductivity on the contrary to that has been reported earlier. Forming of magnetic filed dependent “manganite / (STON, n - Si)“ diode structures has been described, comparative studies of electrical and magnetic properties have been presented, and major electro-physical parameters have been estimated in this work. Possible reasons of the origin of positive and negative magnetoresistance have been pointed out. In addition, structural stabilization problems of BiFeO3 compound, exhibiting at the same time magnetic as well as ferroelectric properties and possibilities of application of its unique properties in various lanthanum manganite structures for the development of new magnetic and electrical filed sensitive device structures have been considered. |
