Supplementary MaterialsSupplementary Information Supplementary Information srep02208-s1. requirements no electroforming procedure, and is offered with rectifying properties which is certainly potentially beneficial to suppress the sneak current in a crossbar architecture. Those particular features open up a promising substitute concept for non-volatile memory devices aswell as Trichostatin-A inhibitor for various other memristive gadgets like synapses in neuromorphic circuits. Resistive switching provides been broadly studied recently because of the potential applications in non-volatile resistive memory gadgets. Generally, resistive switching could be categorized into two primary types: filamentary type1,2,3,4 and user interface type5,6,7,8. It has been accepted that filamentary switching is due to the formation of local conductive filaments, which results from the redistribution of oxygen vacancies9,10 or the diffusion of metal ions.11,12 For interface switching, different mechanisms have been proposed, such as migration of oxygen vacancies13, charge trapping7, or polarization switching14,15. For the interface-related resistive switching, much research work has been focused on the interface where resistive switching takes place. In most cases the stack is designed in a way that this is the interface between top electrode and thin film. For example, Shen et al.16 reported that significantly improved switching performance has been achieved in (Ba,Sr)TiO3 (BST) thin films by using W as top electrode instead of Pt. They attributed this behavior to a reversible oxidation and reduction process at the W/BST interface. Similarly, Liao et al.17 proposed that a thin metal-oxide layer between the top electrode and a Pr0.7Ca0.3MnO3 thin film is important for resistive switching. The formation of this metal-oxide layer is dependent on the Gibbs free energy of oxidation of the top electrodes. Kdr The influence of top electrode material has also been reported for the resistive switching in NiO18 and ZrO19 thin films. In addition, the geometry of the top electrode was identified to play an important role. Fujimot et al.20 observed resistive switching in an Ag paste/Pr0.7Ca0.3MnO3/Pt structure, while no switching could be obtained in a Pt/Pr0.7Ca0.3MnO3/Pt structure, where the Pt top electrode was fabricated by sputtering. They suggested that the Ag paste forms point contacts to the thin film, which induces resistive switching. Nevertheless, in a metal/oxide/metal capacitor structure, the conductivity is not solely determined by the first electrode/oxide interface. The effect of the second oxide/electrode interface has been studied with less intensity when investigating resistive switching behavior. Especially for perovskite thin films, which are usually deposited at high temperatures, the Trichostatin-A inhibitor bottom interface undergoes a high temperature process, thereby the interdiffusion between the thin film and bottom electrode is inevitable. This was often observed in ferroelectric memory fabrication21,22. The interdiffusion between ferroelectric thin film and metal electrode at the bottom interface deteriorates the performance of ferroelectric thin films. In commercially available ferroelectric memory devices the problem is usually circumvented by the oxide bottom electrode that is required to achieve a high endurance in PZT thin films. Therefore, the investigation of bottom interface is also crucial for resistive switching devices, especially when the insulating oxide layer is usually deposited onto a metal bottom electrode at rather high temperatures or takes a subsequent annealing stage. The most famous bottom level electrode for the deposition of several oxide thin movies is certainly Pt. To acquire better adhesion between Pt level and SiO2/Si substrates, a Ti level is normally introduced among. The resulting substrate with Pt electrode includes a framework of Pt/Ti/SiO2/Si. Since Pt is certainly chemically and thermally steady, interdiffusion or response between Pt and the oxide slim films isn’t expected. Nevertheless, the diffusion of adhesion level atoms, right Trichostatin-A inhibitor here Ti atoms, Trichostatin-A inhibitor turns into significant if the slim film includes a high deposition temperatures or is certainly annealed at high temperature ranges after deposition. This diffusion can impact the electric properties of the complete capacitor structure significantly. Up to now, only little function provides been performed upon this issue. For example, Yang et al.23 reported that thermal diffusion of Ti atoms from the adhesion level takes place through the entire Pt level when depositing TiO2 thin movies at 250C. The diffused Ti works as the seeds for conductive filaments and handles the Trichostatin-A inhibitor resistive switching in TiO2. Inside our previous function, a non-volatile bipolar resistive switching provides been reported in BiFeO3 (BFO) thin films which were deposited on Pt/Ti/SiO2/Si substrates24,25. BFO is one of the band of perovskite oxides, and the deposition temperatures of BFO slim films needs to be strictly controlled to be able to avoid the development of impurity phases26..