The polarity origin of the bipolar resistance switching behaviors in metal/La0.7Ca0.3MnO3/Pt junctions

Hwang

Applied Physics Letters

et al. 2012

Resistance random access memory (RRAM) composed of stacked aluminum (Al)/InGaZnO(IGZO)/Al is investigated with different gallium concentrations. The stoichiometric ratio (x) of gallium in the InGaxZnO is varied from 0 to 4 for intentional control of the concentration of the oxygen vacancies (VO), which influences the electrical characteristics of the RRAM. No Ga in the IGZO (x = 0) significantly increases the value of VO and leads to a breakdown of the IGZO. In contrast, a high Ga concentration (x = 4) suppresses the generation of VO; hence, resistive switching is disabled. The optimal value of x is 2. Accordingly, enduring RRAM characteristics are achieved.

mentioning

confidence: 99%

“…These generated oxygen vacancies are thought to cause BRS, triggering a reduction-oxidation reaction with oxygen ions according to the polarity of the applied voltage. 19 The nominal device area used for electrical characterization is 100 lm Â 100 lm. The BE is grounded while a voltage is applied to the TE.…”

mentioning

confidence: 99%

Effects of the oxygen vacancy concentration in InGaZnO-based resistance random access memory

Hwang

Applied Physics Letters

et al. 2012

“…The oxidation near the interface plays a role in the electrical hysteresis and resistance switching. The opposite switching polarity of the Ag/PCMO/Pt device to the Al/PCMO/Pt device is due to the difference in the oxidation Gibbs free energy [41]. …”

Section: Resultsmentioning

confidence: 99%

Thin film deposition of metal oxides in resistance switching devices: electrode material dependence of resistance switching in manganite films

2013

The electric-pulse-induced resistance switching in layered structures composed of polycrystalline Pr1−xCaxMnO3 (PCMO) sandwiched between Pt bottom electrode and top electrodes of various metals (metal/PCMO/Pt) was studied by direct current current–voltage (I-V) measurements and alternating current impedance spectroscopy. The I-V characteristics showed nonlinear, asymmetric, and hysteretic behavior in PCMO-based devices with top electrode of Al, Ni, and Ag, while no hysteretic behavior was observed in Au/PCMO/Pt devices. The PCMO-based devices with hysteretic I-V curves exhibited an electric-pulse-induced resistance switching between high and low resistance states. Impedance spectroscopy was employed to study the origin of the resistance switching. From comparison of the impedance spectra between the high and low resistance states, the resistance switching in the PCMO-based devices was mainly due to the resistance change in the interface between the film and the electrode. The electronic properties of the devices showed stronger correlation with the oxidation Gibbs free energy than with the work function of the electrode metal, which suggests that the interface impedance is due to an interfacial oxide layer of the electrode metal. The interface component observed by impedance spectroscopy in the Al/PCMO/Pt device might be due to Al oxide layer formed by oxidation of Al top electrode. It is considered that the interfacial oxide layer plays a dominant role in the bipolar resistance switching in manganite film-based devices.

“…Several models have been proposed to explain the physical origin of this phenomenon, such as a redox of top electrode41, change of schottky-like barrier with electrochemical migration42, redox of Metal-O-Metal conducting chain29, or Mott metal-insulator transitions43. However, increasing evidence shows that the motion of oxygen ions or vacancies in the vicinity of the electrode area plays an important role for the resistance change in perovskite manganites28293031324445. It has been reported that the RS effect of the perovskite manganite films stems from the break or repair of the -Mn 3+ -O 2− -Mn 4+ - chains induced by the electric field through the oxygen ions or vacancies migration294647.…”

Section: Discussionmentioning

confidence: 99%

Electric field modification of magnetism in Au/La2/3Ba1/3MnO3/Pt device

Xiong

Zhou

et al. 2015

Sci Rep

The La2/3Ba1/3MnO3 film is deposited in a CMOS-compatible Pt/Ti/SiO2/Si substrate with the oxygen pressure of 10 Pa for investigating magnetoelectric effect. Bipolar resistive switching effect with excellent endurance and retention is observed in this Au/La2/3Ba1/3MnO3/Pt device. Through this effect, a significant nonvolatile change of magnetization is obtained in this device as well. The change of magnetization can be understood by the break and repair of the -Mn3+-O2−-Mn4+- chains induced by the electric field through the oxygen vacancies migration. The resistance and magnetization of the Au/La2/3Ba1/3MnO3/Pt device can be simultaneously manipulated by the electric field, which makes it to be a promising candidate for the multifunctional memory devices.