Field-induced Resistance Change Research Articles

Electric Field Induced Resistance Change in PEDOT-PSS Films

Electric Field Induced Resistance Change in PEDOT-PSS Films

Bipolar resistance switching in the fully transparent BaSnO3-based memory device

The fully transparent indium—tin-oxide/BaSnO3/F-doped SnO2 devices that show a stable bipolar resistance switching effect are successfully fabricated. In addition to the transmittance being above 87% for visible light, an initial forming process is unnecessary for the production of transparent memory. Fittings to the current—voltage curves reveal the interfacial conduction in the devices. The first-principles calculation indicates that the oxygen vacancies in cubic BaSnO3 will form the defective energy level below the bottom of conduction band. The field-induced resistance change can be explained based on the change of the interfacial Schottky barrier, due to the migration of oxygen vacancies in the vicinity of the interface. This work presents a candidate material BaSnO3 for the application of resistive random access memory to transparent electronics.

Detailed analyses of electric field-induced resistance switching behavior of SrFeO3−x film

We investigated the electric field-induced resistance change of SrFeO3−x film as a candidate for memory material. SrFeO3−x film showed hysteresis in its current–voltage curve and distinct pulse-switching properties. The resistance of the sample can be switched by the pulse voltage with the length of 50 ns. The relaxation time of the voltage analyses revealed that the resistance-switching properties originate from both the oxygen migration and the charge injection process. Based on these properties, we found that the magnetic state can also be changed by the application of the electric field.

Magnetic and electric field induced resistance change in SrFeO thin film

We have investigated Fe electrode/SrFeO3-x stacking layer as resistance random access memory which is called next generation non-volatile memory. In this stacking system, positive magnetoresistance (MR) due to exchange coupling between Fe electrode and SrFeO3-x layer was observed in initial state. After applying external electric field, in the each resistance state which is high resistance state or low resistance state, MR behaviour was changed from positive MR to negative MR. This behaviour is more likely due to that exchange coupling and the phase of SrFeO3-x layer were changed by electric field and we realized that it is possible to control magnetic property and series of SrFeO3-x phase by using external electric field.

Bipolar resistance switching in the Pt/WO x/W nonvolatile memory devices

We reported the resistive switching behavior in the Pt/WO x/W memory device fabricated with fully room temperature process. The devices show high resistance ratio (>140), reliable data retention at 85 °C and fast switching (100 ns). The field-induced resistance change can be explained based on the formation/rupture of the conduction filaments, due to migration of oxygen vacancies under electric field. The dominant conduction mechanisms of low resistance state and high resistance state were verified by ohmic behavior and trap-controlled space charge limited current, respectively. We demonstrate the present device can be used for multi-bit operation either by compliance current or by reset voltage.

Relationships between Negative Differential Resistances and Resistance Switching Properties of SrFeO<sub>2</sub><sub>+x</sub> Thin Films with Excess Oxygen

Resistance random access memory (RRAM) is attractive as a next-generation form of nonvolatile memory. We investigated an electric field-induced resistance change of SrFeO2+x film as a candidate for RRAM material. SrFeO2.5-x film prepared at 300 oC showed hysteresis in its current-voltage curve and distinct pulse-switching properties. On the other hand, the sample prepared below 280 oC showed hysteresis in its current-voltage curve but didn’t show pulse-switching properties. The amount of oxygen in the sample and easiness of oxygen migration play important roles in the resistance-switching properties.

Electric Field Induced Resistance Change of SrFeO2.5-x Film

Resistance random access memory (ReRAM) is attractive as a next generation nonvolatile memory. We investigated an electric field induced resistance change of SrFeO3-x (SFO) film as a candidate of RRAM material. As-deposited SFO film with high oxygen deficiency, which is expected to have a high oxygen percolation, barely showed hysteresis in current-voltage curve. On the other hand, the annealed sample showed a distinct hysteresis. The amount of oxygen in the sample and easiness of oxygen migration play an important role of the resistance switching properties. [DOI: 10.1380/ejssnt.2010.346]

Magneto-Electric Resistance Modulation of La0.7Sr0.3MnO3 Ferromagnetic Thin Film

We have demonstrated electric field-induced resistance change in a Cr2O3/ultra-thin La0.7Sr0.3MnO3 (LSMO) magnetic heterostructure. By the application of an electric field to the Cr2O3 gate, the resistance of the LSMO film was changed. The temperature dependence of the resistance change has a maximum around 220 K. Since the temperature dependence of the magneto-electric (ME) susceptibility of Cr2O3 has the same tendency, this resistance change is more likely due to the ME effect of the Cr2O3 film. [DOI: 10.1380/ejssnt.2010.318]

Resistance Changes of (La, Sr)MnO<sub>3</sub> Thin Film via Exchange Bias Tuning by the Application of an External Electric Field

We have investigated the relationships between the electric field-induced resistance change and the strength of the exchange interaction of the Cr2O3/ La0.7Sr0.3MnO3 (LSMO) magnetic hetero system. The hetero system subjected to field cooling (FC) showed a positive shift in the magnetization curves due to an exchange bias. The exchange bias field changed depending on the FC field. Resulting from the exchange behaviors, the resistance of LSMO film was changed by the application of an electric field to the Cr2O3 gate. This resistance change is more likely due to the interface interaction strength between the Cr2O3 and LSMO film

Electric field-induced resistance changes at low temperature on a Cr2O3/ultra-thin (La,Sr)MnO3 magnetic hetero structure

We have investigated the relationships between electric field-induced resistance change and the magnetic properties of the Cr 2 O 3 /ultra-thin La 0.7 Sr 0.3 MnO 3 (LSMO) magnetic hetero structure. The LSMO with a thickness of 40 nm has two transition temperatures, the ferromagnetic Curie temperature of 312 K and the spin-glass temperature of 180 K. Resulting from the magnetic properties, the exchange interaction in the Cr 2 O 3 /LSMO behavior below 180 K differed from that below 312 K. With the application an electric field on the Cr 2 O 3 gate, the resistance of LSMO film was changed. This resistance change is most likely due to the magnetic state of LSMO and the interface interaction between the Cr 2 O 3 and LSMO film.

Formation and process optimization of scanning resistive probe

Recently, scanning resistive probe microscopy, which has a semiconducting resistor at the apex of the tip and observes surface charges directly, was newly proposed and fabricated. In order to optimize process parameters as well as to understand the mechanisms of the field induced resistance change in the resistive probe, the doping profile of resistive patterns is investigated by the use of Kelvin probe force microscopy. Overlapping space charge regions (O-SCRs) in between n+ regions were observed. Decreased barrier heights in the structure of n+∕O-SCR∕n+ were also investigated. In particular, resistive patterns with diffusion times longer than 12h were observed to have overlapped outdiffusion of As+ ions, showing no formation of O-SCR in between n+ regions. This was also confirmed by measurements of I-V characteristics.

A simple ambipolar model for the electron-bombardment induced conductivity in amorphous arsenic trisulphide

We reported the resistive switching behavior in the Pt/WOx/W memory device fabricated with fully room temperature process. The devices show high resistance ratio (>140), reliable data retention at 85 °C and fast switching (100 ns). The field-induced resistance change can be explained based on the formation/rupture of the conduction filaments, due to migration of oxygen vacancies under electric field. The dominant conduction mechanisms of low resistance state and high resistance state were verified by ohmic behavior and trap-controlled space charge limited current, respectively. We demonstrate the present device can be used for multi-bit operation either by compliance current or by reset voltage.