Fabrication of the La0.67Ca0.33MnO3 patterns and investigation on I-V characteristic of La0.67Ca0.33MnO3/Nb:SrTiO3

Highlights: • The UV-sensitive LCMO-BPY sol was prepared by adding BPY as a chemical modifier. • A novel microfabrication process without photoresist was studied. • The RS mechanism of In/LCMO/NSTO at two different limiting current is discussed. In this paper, 2,2′-bipyridine (BPY) was used as a chemical modifier to prepare the La_0.67Ca_0.33MnO₃ (LCMO) UV-sensitive sol. The LCMO film was micro-fabricated by the UV-sensitivity of sol, which resulted in LCMO patterns with micron-scale microstructures. The micro-fabrication method was further applied in the preparation of LCMO dot array on the Nb:SrTiO₃ (NSTO) substrate to form In/LCMO/NSTO heterostructure. The I-V curve of the In/LCMO/NSTO structure exhibited an obvious I-V hysteresis window which indicated that the resistive switching (RS) effect occurred. It is analyzed that the RS effect results from the barriers change at the In/LCMO and LCMO/NSTO interfaces. Further tests revealed that the In/LCMO/NSTO structure could exhibited two different I-V characteristics when the limiting current was 1 and 10 mA respectively, and the mechanisms with these two different limiting currents are analyzed based on the interface barrier, Space-charge-limited current mechanism and Fowler-Nordheim tunneling mechanism.