| With the rapid development of information technology, the storage devices have been applied widely. The research and exploitation of permanent memory storage with high speed and large capacity is the prerequisite to promote rapid development of digital technology, resistance random access memory (RRAM) has become the hot issue of materials science, physics and electronics due to its simple structure, high writing/erasing speed, low power consumption and its compatible with CMOS process. At present, RRAM research mainly facing two problems that need to be resolved. First, the essential mechanism of resistance switching has not yet been clarified. Second, the stability, uniformity and endurance of the device need to be improved for the potential application of RRAM materials.In this thesis, with a view of these two problems, the resistance switching of M/Pr0.3Ca0.7MnO3/Pt (M/PCMO/Pt) heterostructures induced by electric field and electric pulses was studied. The main results are as following:1. The Ag electrodes in Ag/PCMO/Pt heterostructure were prepared by three methods, i. e., magnetron sputtering, Pulsed Laser Deposition and air spraying, and the resistance switching properties of the heterostructure were investigated. Experimental results show that the in Ag/PCMO/Pt heterostructure prepared by three methods exhibit different resistance change characteristics. The heterostructure prepared magnetron sputtering shows low switching voltage, high resistance switching ratio, but poorer uniformity and low yield. The samples prepared by PLD show nearly no resistance change characteristics. The samples prepared by air spraying give high yield and good uniformity, but poor fatigue property. In addition, the unstability of the electrode is not suitable for its application. The experiments provide further evidence for the view that resistance change occurs at the interface of the electrode and PCMO film. It also tells us that it is difficult to obtain ideal RRAM devices merely through altering the electrode manufacture method.2. The effect of alloy electrods on the properties of resistance switching in Alloy/PCMO/Pt heterostructures was studied. The Ag-Ti(Alloy), Ag and Ti top electrodes were prepared on PCMO film by Magnetron sputtering respectively. The stability, uniformity, endurance and the yield of the product have been improved remarkably by adjusting the composite and structure of the electrodes. Ag-Ti(Alloy)/ PCMO/Pt heterostructures shows negative bipolar resistance switching (NBRS), which is similar to that in Ag(paste)/PCMO/Pt heterostructures. The Ag-Ti (alloy) /PCMO interface may generate the oxygen-defect-induced interface states. Oxygen ions could fill/leave the vacancy sites in the oxygen-deficient layer when the positive/negative bias is applied. That is to say, the generation/annihilation process of the oxygen vacancy at the oxygen-deficient layer results in the NBRS behavior and trap-controlled SCLC mechanism dominates the current conduction.3. The Ti/Pr0.3Ca0.7MnO3/La0.67Sr0.33MnO3/Pt (Ti/PCMO/LSMO/Pt) heterostructures were prepared by PLD. The introduction of LSMO function layer avoid the direct contact of PCMO film and Pt electrod so that overcome the interface defects between PCMO film and Pt electrode. During resistance switching process, the LSMO layer, serving as an oxygen reservoir, may provides more oxygen ions for PCMO film and improves the resistance switching properties of the heterostructure. The switching properties, especially the fatigue properties, has been greatly improved by inserting LSMO functional layer.
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