Lattice Dislocations Research Articles

High Cycling Rate‐Induced Irreversible TMO6 Slabs Glide in Co‐Free High‐Ni Layered Cathode Materials

AbstractCo‐free high‐Ni layered transition metal oxide is a promising cost‐effective cathode material for high‐energy Li‐ion batteries, but it suffers from undesirable rate performance and rapid capacity decay upon high‐rate cycling. The underlying structural changes under fast electrochemical processes remain unclear to date. In this study, atomic scale structural evolutions of Co‐free high‐Ni layered cathode at different cycling rates are revealed by advanced TEM characterization. It is found that the phase transition after high‐rate cycling is much different from that after low‐rate cycling. The low‐rate cycled sample shows a typical layer‐to‐rock salt transition. However, O1‐type stacking faults are uncovered in the high‐rate cycled sample owing to irreversible TMO6 slabs glide, which induces severe lattice distortion and structural dislocations. These findings deepen the understanding of the rate‐dependent structural degradation mechanism of Co‐free high‐Ni layered cathodes, and have significant implications for improving current materials to withstand high‐rate applications.

Investigations of spray-deposited NiO thin films for ultrasensitive formaldehyde detection

Formaldehyde detection in the environment is the most important due to its carcinogenic effects on human health. In this study, we present the synthesis of nickel oxide (NiO) films at various substrate temperatures with a cost-effective spray pyrolysis technique. Deposited thin films are investigated for micro-structural, topographical, optical and formaldehyde sensing characteristics. According to XRD analysis, the coated films exhibit polycrystalline behavior with cubic structure. Structural specifications such as lattice parameters, crystallite size, strain, dislocation density, and crystallinity of the films are investigated. SEM is used to examine the surface characteristics of the prepared films. The optical bandgap of the sprayed films is calculated from transmittance data utilizing the Tauc plot. Structural distinctions of the NiO films are investigated with Raman spectroscopy. Several harmful gases, including ammonia, ethanol, methanol, acetone, xylene and formaldehyde sensing characteristics have been studied. The material coated at 400 °C has revealed better selectivity and sensitivity of 598 towards 25 ppm of formaldehyde at ambient temperature with a quick response of 16.5 s and recovery of 29.8 s.

A modified Hall-Petch relation for predicting size-induced weakening effect on yield strength of coarse-grained thin films and wires

Tensile yield strength of coarse-grained thin films and wires is size-dependence, exhibiting a “smaller is weaker” phenomenon, which causes a Hall-Petch deviation. Aiming at this problem, a modified Hall-Petch relation is established by considering free-surface effect on lattice dislocation pileup. The modified relations are written as σf=σ0+ck0d-1/2 for films and σf=σ0+c2-ck0d-1/2 for wires, in which c=cosπd/2D and D is the thickness or diameter of samples. The modified Hall-Petch relation is well consistent with experimental results, and the relative error between them is within 15%.

Synthesis of CoFe2O4 Nanomaterials via Sol–Gel Auto‐Combustion Method using Different Chelating Agent, and Its Effects on Magnetic and Dielectric Properties

Herein, the structural and magnetic properties of cobalt ferrite (CoFe2O4 [CFO]) nanomaterials obtained from sol–gel auto‐combustion method using different chelating agent (tartaric acid, citric acid, and oxalic acid) are reported. The obtained precursors from the different chelating agents are calcined at 500 °C for 5 h. The X‐ray diffraction (XRD) analysis suggests that all the synthesized samples show the single‐phase spinel ferrite structure without existing any secondary impurity phases. The lattice parameter, cell volume, density, crystallite size, and dislocation density are computed for all the synthesized samples utilizing the XRD data. The irregular‐shaped grains morphology with a homogeneous distribution is observed through scanning electron microscopy study. The sample synthesized by using the tartaric acid as a chelating agent shows a high magnetization value, highest coercivity, and highest anisotropy constant (K) when compared to those of other chelating agents. High grain‐boundary activation energy is also observed for the CFO nanomaterials obtained from the tartaric acid as a chelating agent.

Synthesis and characterization of (Co1-x Nix)3(BTC)2.12H2O (0 ≤ x ≤ 0.5) MOF based Janus chemical micromotors

We report the synthesis and characterization of Metal–Organic Framework (MOF)-Based Janus chemical Micro motors that self-propel at 26 and 25 µms−1 in 5% and 12% of H2O2, respectively, via ionic diffusiophoresis. The synthesis of this MOF was achieved by solvothermal method. The TG -DT analysis study on (Co1-x Nix)3(BTC)2·12H2O (0 ≤ x ≤ 0.5) micro motors, showed that water ligands can be easily removed. The Co3(BTC)2·12H2O crystallized in orthorhombic crystal system with Pmmm space group and (Co0.8Ni0.2)3(BTC)2·12H2O, (Co1.5Ni1.5)3(BTC)2·12H2O crystallized in monoclinic crystal system with C2 space group. The lattice constants, dislocation density and micro strain of the micro motors were calculated and the structure is discussed in detail using crystal viewer. The morphology of (Co1-x Nix)3(BTC)2·12H2O (0 ≤ x ≤ 0.5) micro motors were scrutinized using the field emission scanning electron microscopy (FE-SEM). Energy dispersion X-ray (EDX) analysis was employed for the elemental analysis and chemical characterization. The vibrational characterization was studied by utilizing Fourier Transform Infrared Spectroscopy (FT-IR) and Raman spectroscopy. The asymmetric and symmetric stretching vibrations of 1,3,5 trisubstituted aromatic ring appeared as three bands at 1368, 1428 and 1219 cm−1. The optical properties were explored using UV–Visible DRS and the absorption edge of Co-BTC, Co0.8Ni0.2-BTC and Co0.5Ni0.5-BTC were observed at approximately 300 nm, 450 nm and 500 nm respectively. The direct band gap for (Co1-x Nix)3(BTC)2.12 H2O (0 ≤ x ≤ 0.5) micromotors was found to be 3.84 eV, 3.76 eV and 3.66 eV respectively. The pore-size distribution and specific surface areas were calculated using Barrett–Joyner–Halenda, BJH and Brunauer Emmett-Teller method respectively. The average pore diameter 8.727 nm and total pore volume of 2.467 × 10−2cm3g−1 was obtained for the material. Insertion of nickel in the lattice of cobalt further accelerates the speed from 0.08 µms−1 to 26µms−1, which leads to a force of 7.29 fN and a power of 4.9 × 10−9 fW, which resembles bio molecular motors. Considering the investigation of MOFS as Microbots/Micromotors so far, Co0.8Ni0.2BTC in both 5% and 12% H2O2 can be represented as the best example of clear observation of bubble tails propelling spherical Janus micromotors.

Deformation mechanism of ripplocation in multilayer graphene

Recently, a new defect known as ripplocation has been discovered in materials with layered structures. In this study, we elucidate the affecting factors in multilayer graphene (MLG) of ripplocation deformation by combining mechanics and mathematics. We perform a molecular dynamics simulation to generate ripplocation deformation by applying local strain to an ABA-type MLG in the armchair direction. The effects of number of graphene layers and graphene widths on ripplocation boundaries (RBs) are discussed comprehensively. Results show that when other conditions remain unchanged, a smaller number of compressed graphene layers and a longer width result in the generation of more RBs with two opposite signs. Furthermore, lattice dislocations are introduced into an ideal MLG to investigate the effect of number of dislocations on the generation of RBs with two opposite signs. We propose a mathematical method using differential geometry to evaluate the mean curvature and obtain a linear relationship between the potential energy and the square of the mean curvature of compressed graphene layers. These results are crucial for evaluating the boundary conditions of corrugated nucleation in layered structures. The proposed method for elucidating ripplocation deformation mechanisms at the nanoscale can be extended to the elucidation of ripplocation behavior in multiscale fields, such as the evaluation of ripplocation deformation of soil layers caused by earthquakes.

Enhancement of catalytic properties and durability in Ni–B–P/Ni foam for hydrazine electrooxidation

Hydrazine is a promising energy carrier of high power density, high theoretical cell voltage, and zero carbon emission to replace fossil fuel-dominated energy sources. Herein, we present a new Ni–B–P/NF catalyst for hydrazine electrooxidation by a facile electroless plating process. The Ni–B–P/NF catalyst exhibits remarkable catalytic activity (290 mA cm−2 at 0.3 V) by combining merits of high intrinsic activity, large specific surface area, satisfactory conductivity, and lattice dislocation. Meanwhile, the Ni–B–P/NF catalyst provides excellent long-term durability (5000 s, 94.4%), which is at the leading level among the reported Ni-based electrocatalysts for hydrazine electrooxidation to date. It is found that the phosphorus-containing coating and its tight binding to the substrate contribute to the long-term durability of Ni–B–P/NF. XPS results and electron models are used to elucidate the electron transition mechanism of the Ni–B–P coating. This work presents a novel catalyst for hydrazine electrooxidation and demonstrates its promising application in energy storage and fuel cell systems.

Mechanisms during Strain Rate-Dependent Crack Propagation of Copper Nanowires Containing Edge Cracks.

The crack propagation mechanism of Cu nanowires is investigated by using molecular dynamics methods. The microstructural evolution of crack propagation at different strain rates and crack depths is analyzed. Meanwhile, the stress intensity factor at the crack tip during crack propagation is calculated to describe the crack propagation process of Cu nanowires under each condition. The simulation results show that the competition between lattice recovery and dislocation multiplication determines the crack propagation mode. Lattice recovery dominates the plastic deformation of Cu nanowires at low strain rates, and the crack propagation mode is shear fracture. With the increase in strain rate, the plastic deformation mechanism gradually changes from lattice recovery to dislocation multiplication, which makes the crack propagation change from shear fracture to ductile fracture. Interestingly, the crack propagation mechanism varies with crack depth. The deeper the preset crack of Cu nanowires, the weaker the deformation resistance, and the more likely the crack propagation is accompanied.

High temperature plasticity at twin boundary in Al: An in-situ TEM perspective

Coherent twin boundaries are of special importance in structural materials due to their strengthening ability by impeding dislocation motion while maintaining possible glide along their plane. Interactions of lattice dislocations with twin boundaries have been extensively studied experimentally and numerically but relaxation and deformation processes at high temperature are not fully understood. The reason is related to complex mechanisms of dislocation decompositions into disconnections, their further motion and possible reactions. Moreover, as in shear-coupled grain boundary (GB) mechanisms, motion of disconnections in the interface plane is expected to lead to twin motion perpendicular to its plane. Here, shear-coupled motion of a coherent twin in pure Al is explored during in situ straining in a transmission electron microscope (TEM) in a favorable geometrical configuration. Surprisingly, the twin boundary does not couple to shear but slightly migrates by propagating nanoscale incoherent facets. Although, disconnections of Burgers vector 1/6〈112〉 have been extensively observed moving in the interface plane, their motion did not lead to migration as expected but presumably to GB sliding. This was interpreted by the motion of disconnections with opposite single and double steps in the [111] direction. Extensive dislocation/GB interactions were observed and reactions following absorption are interpreted by contrast analysis and motion observations. Incoming dislocations do not always decompose but often react with the GB disconnection microstructure which may lead to intergranular motions or dislocation emissions in the adjacent grain. As these processes usually involve disconnection climb in the interface plane, direct transmission, i.e. spatially and temporally correlated absorption/emission processes, is not observed as revealed by large scale observations. Finally, the internal disconnection microstructure of the twin boundary often forms networks which although flexible are found to slow down intergranular plasticity. Such networks should strongly control stress induced mechanisms in realistic GBs.

Lattice parameters of austenite and martensite during transformation for Fe–18Ni alloy investigated through in-situ neutron diffraction

Martensitic transformation is accompanied by the generation of microscale and macroscale internal stresses during cooling below the martensitic transformation start temperature. These internal stresses have been determined through X-ray or neutron diffraction, but the reported results are not consistent, probably because the measured lattice parameter is influenced not only by the internal stress but also by several factors, including solute elements and crystal defects. Therefore, in-situ neutron diffraction combined with dilatometry measurements during martensitic transformation and subsequent cyclic tempering were performed for an Fe–18Ni alloy. The phase strains calculated by lattice parameter variations show that a hydrostatic compressive strain in austenite and a tensile strain in martensite arose as the martensitic transformation progressed during continuous cooling or isothermal holding. However, the phase stresses of austenite and martensite estimated from these strains failed to hold stress balance law when dense crystal defects involved in the processes. After these crystal defects were removed by appropriate tempering, the stress balance law held well. Meanwhile, the phase stresses of austenite and martensite were changed to opposite, revealing their true identity. Furthermore, the lattice parameter of quenched full martensite and the specimen diameter were both decreased by tempering, demonstrating that there is a direct correlation among lattice parameter, specimen volume and dislocation density. As a result, various crystal defects in austenite and martensite, introduced by plastic accommodation, were suggested to affect their lattice parameters and then their phase stresses.

Effect of Er, Si, Hf and Nb Additives on the Thermal Stability of Microstructure, Electrical Resistivity and Microhardness of Fine-Grained Aluminum Alloys of Al-0.25%Zr.

The conductor aluminum alloys of Al-0.25wt.%Zr alloyed additionally with X = Er, Si, Hf and Nb were the objects of our investigations. The fine-grained microstructure in the alloys was formed via equal channel angular pressing and rotary swaging. The thermal stability of the microstructure, specific electrical resistivity and microhardness of the novel conductor aluminum alloys were investigated. The mechanisms of nucleation of the Al3(Zr, X) secondary particles during annealing the fine-grained aluminum alloys were determined using the Jones-Mehl-Avrami-Kolmogorov equation. Using the Zener equation, the dependencies of the average secondary particle sizes on the annealing time were obtained on the base of the analysis of the data on the grain growth in the aluminum alloys. The secondary particle nucleation during long-time low-temperature annealing (300 °C, 1000 h) was shown to go preferentially at the cores of the lattice dislocations. The Al-0.25%Zr-0.25%Er-0.20%Hf-0.15%Si alloy subjected to long-time annealing at 300 °C has the optimal combination of microhardness and electrical conductivity (59.8%IACS, Hv = 480 ± 15 MPa).

Effect of metal ions on structural, morphological and optical properties of nano-crystallite spinel cobalt-aluminate (CoAl2O4)

The bright blue nano crystallite cobalt aluminate (CoAl2O4) was synthesized by sol–gel method using a mixture of chelating agent of glycerol and citric acid. The effects of changing (0.05, 0.075, 0.10, 0.25, 0.50, and 0.75 mol/L) metal ion concentration on the structural, morphological and color properties of synthesized CoAl2O4 were characterized by using X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), Nanoparticle size analyzer, Simultaneous Thermal Analyzer (STA), UV–vis absorption spectroscopy, and CIE-LAB colorimetric analysis. From the X-ray peak profile analysis, the crystallite size was measured by Debye-Scherrer (D-S) equation, and three different models presenting average crystallite sizes between 88.3 and 125.4 nm.The average lattice strain, dislocation density, lattice constant, cell volume, and zeta potential were between 0.00021 and 0.0058, (1.73 to 12.8) × 1014 (lines/m2), 8.10658 to 8.11181 Å, 533.60 to 533.81 Å3, −56.4 to − 63.5 mV, respectively. Using UV–vis absorption spectroscopy, the band gap was calculated from Kubelka-Munk method, and the values of band gap increasing from 1.82 to 1.84 eV, respectively. The reflectance spectra and the CIE-L*a*b* values of cobalt aluminate is also measured which confirmed the formation of blue nano crystallite cobalt aluminate.

A Study of Lithium Ferrite and Vanadium-Doped Lithium Ferrite Nanoparticles Based on the Structural, Optical, and Magnetic Properties

Lithium ferrite and vanadium-doped lithium ferrite have been extensively studied in recent research because of their potential applications in thermochromic materials, optoelectronic devices, and as a cathode material for rechargeable lithium batteries. In the present investigation, lithium ferrite and lithium vanadium ferrite are synthesized by sol–gel process. According to the Scherrer formula, the average particle size of lithium ferrite is 22 nm and that of vanadium-doped lithium ferrite is 29 nm. The lattice parameters and dislocation density are calculated from the X-ray diffraction results. According to the Fourier transform infrared spectroscopy analysis, ferrites were formed that exhibit strong absorption bands. According to the energy-dispersive X-ray analysis spectrum, the predicted elements are present in the sample. With the use of a vibrating sample magnetometer (VSM), the materials’ magnetic behavior is investigated.

Effect of Lattice Constants and Precipitates on the Dimensional Stability of Rolled 2024Al during Isothermal Aging

The change in material dimensional will lead to the decline of instrument accuracy and reliability. In this paper, the characterization and analysis of the lattice constant, precipitates, and dislocation density of the material by X-ray diffraction (XRD) and transmission electron microscopy (TEM) reveals the reason why the relative dimensional change in the rolled 2024Al is one order of magnitude lower than that of the as-cast 2024Al during isothermal aging. Compared with as-cast 2024Al, the dislocation density of rolled 2024Al is higher, the lattice constant decreases less before and after aging, and the precipitates have orientation and more content, resulting in the dimensional change in rolled 2024Al being smaller than that of as-cast 2024Al. In addition, two main reasons for decreasing the dimensional change in rolled 2024Al are discussed: the decrease in lattice constant, the formation and growth of the S phase before and after aging.

Corrosion resistance and mechanical properties of electrodeposited Co-W/ZrO2 composite coatings

Co-W/ZrO2 composite coatings were prepared on copper substrate by electrodeposition technology, and the effect of the concentration of ZrO2 particles in the plating solution on the content of ZrO2 particles in the composite coating, the corrosion resistance, and mechanical properties of the composite coating were studied. The results show that as the concentration of ZrO2 particles in the plating solution increases from 3 g/L to 26 g/L, the content of ZrO2 particles in the composite coating first increases and then decreases, and the grains shape and compactness of the composite coating change significantly, resulting in differences in the corrosion resistance, hardness, wear resistance and tensile strength. Appropriate amount of ZrO2 particles in the plating solution can increase the content of ZrO2 particles in the composite coating, which may cause a greater degree of lattice distortion and dislocation leading to compact surface morphology and better mechanical properties. The composite coating prepared when the concentration of ZrO2 particles in the plating solution is 18 g/L is composed of face-centered cubic structure Co, close-packed hexagonal structure Co and Co3W phases with 7.35% ZrO2 particles. The composite coating has many densely arranged elongated structures, and exhibits the best corrosion resistance and mechanical performance with charge transfer resistance of 7056 Ω·cm2, low-frequency impedance of 6960 Ω·cm2 and phase angle of 66.5°, hardness of 573.2 HV0.05 and tensile strength of 206.8 MPa, which are all higher than Co-W alloy coating.

Magnetron-sputtered Mg-Ga co-doped ZnO transparent conductive thin films: Microstructural and optoelectrical investigation

The Mg–Ga co-doped ZnO (MGZO) transparent conducting thin films (TCTFs) were fabricated via magnetron-sputtering. The dependence of microstructural, morphological and optoelectrical characteristics on sputtering power was investigated. The findings demonstrate that all the TCTFs present a wurtzite hexagonal crystal structure and (002)-preferred orientation. The sputtering power has a significant impact on the properties of the TCTFs. The sample fabricated at 150 W possesses the highest optoelectrical performance and crystalline quality, with the maximum figure of merit, highest average visible transmittance, minimum resistivity, lowest dislocation density and lattice strain of 1.042×104 Ω−1·cm−1, 92.21%, 1.181×10−3 Ω·cm, 1.041×1011 cm−2 and 3.936×10−3, respectively. Moreover, the optical constants (OCs) of the MGZO TCTFs were extracted by the optical spectrum fitting method (OSFM). The dispersion behavior of refractive index (RI) was assessed. The oscillator parameters, optical bandgaps and nonlinear OCs were realized. This study provides a reference basis for the applications of MGZO TCTFs in photoelectronic devices.

A Microphysical Model of Rock Friction and the Brittle‐Ductile Transition Controlled by Dislocation Glide and Backstress Evolution

AbstractRate‐ and state‐friction (RSF) is an empirical framework that describes the complex velocity‐, time‐, and slip‐dependent phenomena observed during frictional sliding of rocks and gouge in the laboratory. Despite its widespread use in earthquake nucleation and recurrence models, our understanding of RSF, particularly its time‐ and/or slip‐dependence, is still largely empirical, limiting our confidence in extrapolating laboratory behavior to the seismogenic zone. While many microphysical models have been proposed over the past few decades, none have explicitly incorporated the effects of strain hardening, anelasticity, or transient elastoplastic rheology. Here we present a new model of rock friction that incorporates these phenomena directly from the microphysical behavior of lattice dislocations. This model of rock friction exhibits the same logarithmic dependence on sliding velocity (strain rate) as RSF and displays a dependence on the internal backstress caused by long‐range interactions among geometrically necessary dislocations (GNDs). Changes in the backstress (internal stress) evolve exponentially with plastic strain of asperities and are dependent on both the current backstress and previous deformation, which give rise to phenomena consistent with interpretations of the “critical slip distance,” “memory effect,” and “evolution effect” of RSF. The rate dependence of friction in this model is primarily controlled by the evolution of backstress and temperature. We provide several analytical predictions for RSF‐like behavior and the “brittle‐ductile” transition based on microphysical mechanisms and measurable parameters such as the GND density and strain‐dependent hardening modulus.

Effect of Tempforming on Strength and Toughness of Medium-Carbon Low-Alloy Steel.

The effect of tempforming on the strength and fracture toughness of 0.4%C-2%Si-1%Cr-1%Mo-VNb steel was examined. Plate rolling followed by tempering at the same temperature of 600 °C increases yield stress by 25% and the Charpy V-notch impact energy by a factor of ~10. Increasing rolling reduction leads to the reorientation and elongation of grains toward the rolling direction (RD) and the development of a strong {001} <110> (rotated cube) texture component that highly enhances fracture toughness. A lamellar structure with a spacing of 72 nm between boundaries and a lattice dislocation density of ~1015 m-2 evolves after tempforming at 600 °C with a total strain of 1.4. Two types of delamination were found, attributed to crack branching and the propagation of secondary cracks along the rolling plane perpendicular to the propagation direction of the primary crack. Delamination toughness is associated with the nucleation of secondary cracks in RD and their propagation over a large distance. The critical condition for delamination toughness is the propagation of primary cracks by the ductile fracture mechanism and the propagation of secondary cracks by the brittle quasi-cleavage mechanism.

Influence of Al and Cu Doping on the Structure, Morphology, and Optical Properties of ZnO Thin Film

In this study, ZnO thin films doped with Al (AZO) and Cu (CZO) were fabricated on a glass substrate via sol-gel spin coating. The influence of 1 atomic % Al and Cu doping on the structure, morphology, as well as optical properties of ZnO thin film was then analyzed with X-ray diffraction (XRD), atomic force microscopy (AFM), and UV-Vis spectroscopy. XRD analysis revealed that all samples possessed hexagonal wurtzite crystal structures with 3 to 4 preferred orientations. Al and Cu doping caused a decrease in crystal size, while the lattice strain (e) and dislocation density (ρ) were increased. AFM indicated that Al and Cu doping reduced the surface roughness of the ZnO thin film. Optical measurement showed that all samples exhibited high transmittance (&gt; 80%) in the visible light region. Transmittance was reduced after doping, while the band gaps for ZnO, AZO, and CZO thin films are 3.26, 3.28, and 3.23 eV. This study showed that an addition of 1 atomic % transition metal (Al and Cu) greatly influences the structure, morphology, and optical properties of ZnO thin film.

Initiation and Mechanisms of Plasticity in Bimetallic Al-Cu Composite

We studied the shear deformation of a laminar Al-Cu composite with (100) and (110) interfaces with a shear perpendicular to the lamellae in comparison with pure single crystal Al and Cu at strain rates of 109 s−1 and 108 s−1 and different initial pressures in the range from −3 GPa to +50 GPa. The results of molecular dynamics (MD) for the plasticity initiation are generalized by means of an artificial neural network (ANN) trained by MD data for the (100) interface, and a rate sensitivity parameter identified using MD data for different strain rates. The ANN-based approach allows us to extrapolate MD data to much lower strain rates, which are more relevant for typical dynamic loadings. The considered problem is of interest as an example of the application of the developed ANN-based approach to bimetallic systems, whereas previously it was tested only for pure metals; in addition, Al-Cu composites are of practical interest for technology. The interface between metals reduces the shear strength of the composite in comparison with both pure metals. At an initial pressure below 10 GPa, the plasticity begins in the aluminum part of the composite, while at higher pressures, the plasticity of the copper part starts first. At a pressure above 40 GPa, a phase transition in the aluminum part governs the plasticity development. All this leads to a nonmonotonic pressure dependence of the critical shear stress of the Al-Cu composite in the case of (100) and (110) interfaces without misorientation. Misorientation decreases the critical stress of the nucleation of lattice dislocation and makes the pressure dependence of this stress monotonic. Deformation modes, with a defect-free copper part and a strain-accommodating aluminum part are observed in the MD and can be useful for technological applications related to deformable conducting materials.