Contact Engineering Approach to Improve the Linearity of Multilevel Memristive Devices

Physical mechanisms underlying the multilevel resistive tuning over seven orders of magnitude in structures based on TiO2/Al2O3 bilayers, sandwiched between platinum electrodes, are responsible for the nonlinear dependence of the conductivity of intermediate resistance states on the writing voltage. To improve the linearity of the electric-field resistance tuning, we apply a contact engineering approach. For this purpose, platinum top electrodes were replaced with aluminum and copper ones to induce the oxygen-related electrochemical reactions at the interface with the Al2O3 switching layer of the structures. Based on experimental results, it was found that electrode material substitution provokes modification of the physical mechanism behind the resistive switching in TiO2/Al2O3 bilayers. In the case of aluminum electrodes, a memory window has been narrowed down to three orders of magnitude, while the linearity of resistance tuning was improved. For copper electrodes, a combination of effects related to metal ion diffusion with oxygen vacancies driven resistive switching was responsible for a rapid relaxation of intermediate resistance states in TiO2/Al2O3 bilayers.

Download Full-text

Ultrahigh energy storage and ultrafast ion diffusion in borophene-based anodes for rechargeable metal ion batteries

Journal of Materials Chemistry A ◽

10.1039/c6ta09730h ◽

2017 ◽

Vol 5 (5) ◽

pp. 2328-2338 ◽

Cited By ~ 73

Author(s):

Dewei Rao ◽

Lingyan Zhang ◽

Zhaoshun Meng ◽

Xirui Zhang ◽

Yunhui Wang ◽

...

Keyword(s):

Energy Storage ◽

Metal Ion ◽

High Performance ◽

Storage Systems ◽

Ultrahigh Energy ◽

Ion Diffusion ◽

Energy Storage Systems ◽

Increasing Demand

Since the turn of the new century, the increasing demand for high-performance energy storage systems has generated considerable interest in rechargeable ion batteries.

Download Full-text

The oxidation of iron around 200 °C

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1953.0028 ◽

1953 ◽

Vol 216 (1126) ◽

pp. 375-397 ◽

Cited By ~ 28

Keyword(s):

Oxygen Uptake ◽

Metal Ion ◽

Absolute Temperature ◽

Ion Diffusion ◽

Surface And Interface ◽

Air Interface ◽

Original Metal ◽

Logarithmic Relationship ◽

Boundary Reaction ◽

Heterogeneous Layer

Phenomena associated with a critical temperature at ca . 200° C in the oxidation of mild steel sheet in air (for example, a change of slope in the curve relating reciprocal of absolute temperature with logarithm of oxygen uptake in constant time) have been investigated by gravimetric, microchemical and electron-diffraction methods. The evidence is interpreted on the basis of predominant metal-ion diffusion above and predominant oxygen-ion diffusion below 200° C, in the oxide film. In the film an outer layer of rhombohedral α -Fe 2 O 3 , overlies a layer of cubic oxide which, initially nearer γ -Fe 2 O 3 , tends towards Fe 3 O 4 —rapidly and completely above 200° C, slowly and incompletely below 200° C. Above 200° C the rate of oxidation is controlled by the diffusion of ions across the film (Wagner mechanism), the parabolic law is followed, and oxygen uptake derived from the weight increase of the specimen is coincident with the oxygen content of the film on removal from the substrate. The film, being produced outside the original metal/air interface, is relatively insensitive to the mode of preparation of the surface, and interface colours readily develop. Below 200° C, oxidation again involves ion diffusion across the film, but the rate is controlled by a boundary reaction with a consequent logarithmic relationship with time. Since oxidation now proceeds at an oxide-metal interface the optical homogeneity of the oxidized layer is very sensitive to the initial condition of the surface. Abraded surfaces carry initially a heterogeneous layer (abrasion-produced oxide in a matrix of iron) in which oxidation can proceed without contributing to the overlying (strippable) film on which the development of interference colours depends. Thickening of the film and progression of colours may be long delayed during the period of oxygen uptake within the substrate. This period may be eliminated or. reduced either by removal of the heterogeneous layer by acid etching or by its modification by vacuum annealing. Although the disturbed substrate on abraded specimens serves in this way to provide evidence for the inward diffusion of oxygen, it exerts no appreciable control over the total oxygen uptake either above or below 200° C.

Download Full-text

Hopping Conduction in Intermediate Resistance State of Tantalum Oxide Resistive Switching Memory

ECS Meeting Abstracts ◽

10.1149/ma2016-02/16/1462 ◽

2016 ◽

Keyword(s):

Resistive Switching ◽

Tantalum Oxide ◽

Hopping Conduction ◽

Resistive Switching Memory ◽

Intermediate Resistance ◽

Resistance State ◽

Switching Memory

Download Full-text

Nonlinear dependence of set time on pulse voltage caused by thermal accelerated breakdown in the Ti/HfO2/Pt resistive switching devices

Applied Physics Letters ◽

10.1063/1.4766737 ◽

2012 ◽

Vol 101 (20) ◽

pp. 203502 ◽

Cited By ~ 29

Author(s):

M. G. Cao ◽

Y. S. Chen ◽

J. R. Sun ◽

D. S. Shang ◽

L. F. Liu ◽

...

Keyword(s):

Resistive Switching ◽

Pulse Voltage ◽

Nonlinear Dependence ◽

Switching Devices

Download Full-text

Greenhouse and Field Resistance to Yellow Aphids in the `Pawnee' Pecan

HortScience ◽

10.21273/hortsci.32.3.494e ◽

1997 ◽

Vol 32 (3) ◽

pp. 494E-494 ◽

Cited By ~ 2

Author(s):

Tommy E. Thompson ◽

L.J. Grauke

Keyword(s):

Field Tests ◽

Field Resistance ◽

Carya Illinoinensis ◽

The West ◽

Large Numbers ◽

Leaf Surfaces ◽

Intermediate Resistance ◽

Insect Populations ◽

Greenhouse Tests ◽

Aphid Populations

Putative resistance to the yellow aphid complex (Monellia caryella (Fitch) and Monelliopsis pecanis Bissell) in the `Pawnee' pecan [Carya illinoinensis (Wangenh.) K. Koch] cultivar was first noted in greenhouse tests by rating cultivars for relative amounts of honeydew on adaxial leaf surfaces. This resistance was confirmed in two field tests monitored from mid-June to mid-Oct. `Pawnee' supported significantly lower aphid populations during every rating period when relatively large numbers of these insects were present. `Navaho' also showed resistance, with `Desirable' having intermediate resistance and `Stuart' being very susceptible. Insect populations were also monitored on the four quadrants of each tree, with this quadrant effect being significant in only one test. This test had the highest populations on the West and lowest populations on the East.

Download Full-text

Application of MXene-based materials in hybrid capacitor

Sustainable Energy & Fuels ◽

10.1039/d1se00448d ◽

2021 ◽

Author(s):

Le Li ◽

Dan Zhang ◽

Jianping Deng ◽

Yuchun Gou ◽

Junfei Fang ◽

...

Keyword(s):

Transition Metal ◽

Metal Ion ◽

Layered Materials ◽

Low Energy ◽

Metal Carbides ◽

Ion Diffusion ◽

Energy Barriers ◽

Crystal Nucleus ◽

Transition Metal Carbides

MXenes, a noble category of 2D transition metal carbides or nitride-layered materials, exhibit special electroconductibility in a crystal nucleus, low-energy barriers for metal ion diffusion, satisfactory layer spaces for ion...

Download Full-text

An investigation of metal ion diffusion in ceria‐based solid oxide fuel cell with barium‐containing anode

Journal of the American Ceramic Society ◽

10.1111/jace.15796 ◽

2018 ◽

Vol 101 (12) ◽

pp. 5791-5800 ◽

Cited By ~ 3

Author(s):

Jiafeng Cao ◽

Yuexia Ji ◽

Xuejun Zhou ◽

Chunxiang Cao ◽

Xianmei He ◽

...

Keyword(s):

Fuel Cell ◽

Solid Oxide Fuel Cell ◽

Metal Ion ◽

Solid Oxide ◽

Oxide Fuel ◽

Ion Diffusion

Download Full-text

Multilevel resistive switching memory behaviors arising from ion diffusion and photoelectron transfer in α-Fe2O3 nano-island arrays

Physical Chemistry Chemical Physics ◽

10.1039/c9cp06392g ◽

2020 ◽

Vol 22 (5) ◽

pp. 2743-2747 ◽

Cited By ~ 1

Author(s):

Zhijun Ren ◽

Guangdong Zhou ◽

Shiqiang Wei

Keyword(s):

Bias Voltage ◽

Resistive Switching ◽

Ion Diffusion ◽

Resistive Switching Memory ◽

Switching Memory

Resistive switching (RS) memory behaviors are observed in an Ag|α-Fe2O3|Ti device after operating under an ultralow bias voltage of ±0.1 V.

Download Full-text

Nucleotide hydrolysis regulates the dynamics of actin filaments and microtubules

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.1992.0048 ◽

1992 ◽

Vol 336 (1276) ◽

pp. 93-97 ◽

Cited By ~ 14

Keyword(s):

Protein Interactions ◽

Actin Filaments ◽

Metal Ion ◽

Dynamic Instability ◽

Dynamic Properties ◽

Monomer Concentration ◽

Nonlinear Dependence ◽

Nucleotide Hydrolysis ◽

Conformational Switch

Actin filaments and microtubules are major dynamic components of the cytoskeleton of eukaryotic cells. Assembly of these polymers from monomeric actin or tubulin occurs with expenditure of energy, because ATP (or GTP) tightly bound to actin (or tubulin) is irreversibly hydrolysed during polymerization. Therefore, actin filaments an microtubules are dissipative structures. Our purpose has been to understand how the dissipation of chemical energy perturbs the laws of reversible helical polymerization defined by Oosawa, and affects the dynamics of these polymers. A kinetic study has shown that nucleotide is hydrolysed on the polymer within at least two steps consecutive to the incorporation of the monomer: cleavage of the γ-phosphoester bond followed by the slower release of P i ; only the second reaction appears reversible. P i release, and not cleavage of the γ-phosphate, is linked to the destabilization of protein-protein interactions in the polymer, and therefore plays the role of a conformational switch. The dynamic properties of the polymer in the NTP- and NDP-P i intermediate states of the assembly process have been investigated using non-hydrolysable analogues of nucleotides and structural analogues of P i , AIF 4 - and (BeF 3 - , H 2 O). Because nucleotide hydrolysis is uncoupled from polymerization, actin filaments and microtubules grow with a ‘cap’ of terminal NTP- and NDP-P i - subunits that interact strongly, and prevent the rapid depolymerization of the unstable core of the polymer formed of NDP-subunits. The fact that the dynamic properties of the polymer are affected by bound nucleotide results in a nonlinear dependence of the rate of elongation on monomer concentration. This nonlinearity accounts for the dynamic instability behaviour of microtubules, which is an important feature of their function, and explains the oscillatory polymerization kinetics in a population of synchronized microtubules. The above analysis provides the basis for anticipating possible modes of regulation of cytoskeletal assembly via modulation of the rate of nucleotide hydrolysis. The role of the metal ion (Ca 2+ , Mg 2+ ) chelated to the β- and γ-phosphates of ATP (or GTP) and the stereochemistry of nucleotide binding to actin and tubulin have been studied using the CrATP and CrGTP β γ-bidentate analogues of MgATP and MgGTP. The changes in the environment of the triphosphate moiety of the nucleotide following the release of P i ; on Factin, and of Mg 2+ and P i ; on microtubules, is proposed as being part of the conformational switch leading to the destabilization of the polymers.

Download Full-text