Interface Width Research Articles

Topological interface states - A possible path towards a Landau-level laser in the THz regime

Volkov-Pankratov surface bands arise in smooth topological interfaces, interfaces between a topological and a trivial insulator, in addition to the chiral surface state imposed by the bulk-surface correspondence of topological materials. These two-dimensional bands become Landau-quantized if a magnetic field is applied perpendicular to the interface. I show that the energy scales, which are typically in the 10-10010−100 meV range, can be controlled both by the perpendicular magnetic field and the interface width. The latter can still be varied with the help of a magnetic-field component in the interface. The Landau levels of the different Volkov-Pankratov bands are optically coupled, and their arrangement may allow one to obtain population inversion by optical pumping. This could serve as the elementary brick of a multi-level laser based on Landau levels. Moreover, the photons are absorbed and emitted either parallel or perpendicular to the magnetic field, respectively in the Voigt and Faraday geometry, depending on the Volkov-Pankratov bands and Landau levels involved in the optical transitions.

(Ti, Nb)(C, B)/IN625 In-Situ Reactive Coating Prepared by Ultra-High-Speed Laser Cladding: Interfacial Characterization, Residual Stress and Surface Wear Mechanisms

In this study, homogeneous (Ti, Nb)(C, B)/IN625 composite coatings with almost defect-free microstructures were successfully prepared on a 42CrMo steel substrate by coupling ultra-high-speed laser cladding (USLC) with the direct reaction synthesis (DRS) technique to introduce the in-situ exothermic reaction into the cladding materials; these were comparatively analyzed with the pure IN625 coating prepared only by USLC. Our results showed that the interface of the composite coating/substrate was greatly affected by about 670 kJ Joule heat released from the in-situ reaction happening during the cladding process, which was sufficient to remelt the as-deposited materials and significantly increased the coating/substrate interface width to around 24 μm, six times the interface width of pure IN625 coating. Furthermore, the residual stress inside the coating and across the interfacial region was also reduced, alleviating the interface stress mismatch. However, the surface hardness of (Ti, Nb)(C, B)/IN625 composite coating was found to be lower than that of the IN625 coating, and the average wear weight loss was only 10% of that of the IN625 coating, attributable to the in-situ authigenic TiCB, TiC, NbMo3B4 and NbMo2B2 phases providing load transfer from the hard phases to the IN625 composite matrix to achieve abrasion reduction and wear resistance. It was also found that the formation of nano-equiaxial ultrafine grains in the depth range of 250 nm below the wear surface was facilitated by the coupling of the three fields of plastic rheology-heat-force, which dynamically strengthened the wear surface. Based on these findings, it is suggested to promote the strategy of combing USLC and DRS techniques to achieve an additional ability to enhance the coating microstructure and reduce residual stress, to achieve better tribological performance.

Junction dynamics in phase-field simulations vis-à-vis asymptotics predictions : A beginning study

An ideal situation in phase-field methodology is when realistic evolution dynamics can be simulated at much larger interface widths. Asymptotic analysis, at best, can only help half address the challenge. It might give insights for making model adjustments so as to capture the appropriate sharp-interface description up to various orders of accuracy. However, this still is insufficient to conclude if artificial enlargement of interfacial thickness to desirable degree is permissible. Laborious numerical tests and crosschecks have to be performed to find it out. The current work will emerge to stand as a classic example for such a scenario. It is seen that sensitivity to modeling choices is more pronounced in the case of evolution of junctions than it is anywhere else. In particular, we noticed that interfacial mobility interpolating forms or formulations can put up severe restrictions on the required interface widths for reproducing close to converged sharp-interface behaviors. To make things worse, this is highly system dependent, i.e., the same material system considered in a different setup, or the same setup when considered for different material systems can require a change in mobility formulation for faster recovery of the limiting dynamics. Also, it is found that the traditional recipe popularly adopted for carrying out interface-width reduction studies is unsustainable and has to be replaced by a costlier routine.

Recovering critical parameter for nonlinear Allen–Cahn equation by fully discrete continuous data assimilation algorithms *

The purpose of this study is to recover the diffuse interface width parameter for nonlinear Allen–Cahn equation by a continuous data assimilation algorithm proposed recently. We obtain the large-time error between the true solution of the Allen–Cahn equation and the data assimilated solution produced by implicit–explicit one-leg fully discrete finite element methods due to discrepancy between an approximate diffuse interface width and the physical interface width. The strongly A-stability of the one-leg methods plays key roles in proving the exponential decay of initial error. Based on the long-time error estimates, we develop several algorithms to recover both the true solution and the true diffuse interface width using only spatially discrete phase field function measurements. Numerical experiments confirm our theoretical results and verify the effectiveness of the proposed methods.

Interfacial reactivity in the Co/CuO samples as investigated by x-ray photoelectron spectroscopy

The interfacial reactivity at the Co/CuO interfaces has been investigated in situ by the technique of x-ray photoelectron spectroscopy. Thin films of cobalt were evaporated on the CuO substrates by the technique of e-beam. The depositions were undertaken by maintaining the substrates at ambient temperature. Significant differences have been observed in the Cu 2p core level spectra recorded for these samples and that for pure CuO. The Co 2p core level spectrum also shows differences upon comparison with the spectrum for elemental cobalt. These differences arise from chemical interaction occurring at the Co/CuO interface. The curve fitting technique has been utilized to estimate the relative percentages of the constituents at the interface. The interface width has been determined from the relative percentage of the unoxidized cobalt present in the overlayer. The dependence of the interface width has also been explored as a function of annealing temperature. The interface width is much less for the room temperature deposited sample as compared to that for annealed samples. The spectral data also indicate increase in the diffusion of copper oxide through the cobalt overlayer with increasing temperature.

Tuning of exchange bias by regulating the microstructural parameters in Ni81Fe19 (5, 8, 11, 14, 17, and 20 nm)/Ir7Mn93(10 nm) bilayers probed using magnetoresistance

The investigation and tunning of positive exchange bias (PEB) and negative exchange bias (NEB) are reported at room temperature (RT) and low temperature (20 K), respectively, in a series of top-pinned Ni81Fe19(tFM = 5, 8, 11, 14, 17, and 20 nm)/Ir7Mn93(10 nm) polycrystalline heterostructure thin films grown in the presence of a 1 kOe in situ magnetic field by systematically controlling the microstructural parameters such as thickness, roughness, and crystallite/grain size. On decreasing the thickness (roughness) of NiFe from 20 nm (0.49 nm) to 5 nm (0.28 nm), an enhancement in PEB and NEB is observed from +12 to +22 Oe and −300 to −556 Oe at RT and 20 K, respectively. It is observed that both exchange bias and coercivity substantially depend on the atomic scale roughness of the interface width (NiFe/IrMn). The representative plane-view of transmission electron microscopy (TEM) measurements revealed the enhanced antiferromagnet (AF) grain size on decreasing the thickness of ferromagnetic, whereas cross-sectional TEM studies exhibited the sharp interfaces in the bilayer samples after magnetic annealing. A unique correlation between the training mechanism and the degree of asymmetry is established. Further, the training measurement data are fitted with various theoretical models that support the fact that not only interfacial but also bulk AF spins play a vital role in the exchange bias. Thus, the present study reveals the microstructural insights by varying the thickness of NiFe to address the unresolved issues of the EB by directly correlating it with interface roughness and the crystallite/grain size of AF in it, probed using the magnetoresistance technique.

Research on the green preparation of manufactured sand by tuff produced in Gansu China and its influence on the properties of concrete

Tuff in Gansu Province, China, is a parent rock with abundant reserves. Studying the characteristics of this parent rock and developing advanced technology for manufacturing its sand are valuable scientific endeavors. The physical and mechanical properties, chemical composition, pore structure, and lithofacies of the parent rock of tuff in the study region were examined in this study. The crushing and impact characteristics of the tuff were analyzed to propose a set of novel key processes and parameters for the production of manufactured sand from tuff in the Gansu region. Using the technology proposed in this study, tuff-manufactured sand was produced and used to prepare concrete. The effects of the tuff-manufactured sand on the flowability, hydration process, mechanical properties, pore structure, and interface transition zone (ITZ) of the concrete were systematically studied. The research results show that the SiO2 content in tuff is as high as 55.45 %, making it a neutral alkaline stone with a compressive strength of 48.0 MPa. The Bangde ball milling work index and impact work index of tuff was 9.89KW/t and 6.45, respectively. And the tuff is easy to break and more stone powder will be produced during the preparation of manufactured sand. The “two-stage crushing and three-stage screening” preparation process and key parameters for tuff-manufactured sand were proposed for the first time. Compared with traditional granite, the slump of tuff-manufactured sand concrete was reduced by 2.38 %, and the compressive strength was increased by 8.56 %. The stone powder in the tuff-manufactured sand participated in a hydration reaction before 14 h of hydration. Compared with river sand concrete, the total number of pores of tuff-manufactured sand concrete decreased by 49.18 %, ITZ split tensile strength and ITZ vulnerable point microhardness increased by 30.91 %, ITZ thickness decreased by 21.05 %, and the maximum crack width of aggregate and ITZ contact interface decreased by 0.47 μm after standard curing for 28 d.

Experimental investigation of the interfacial bonding properties between polyurethane mortar and concrete under different influencing factors

As a repair material, polyurethane mortar has excellent mechanical properties. The aim of this study is to explore the mechanical properties and microstructure of the interface between polyurethane mortar and concrete. The effects of curing temperature (−20 °C, −10 °C, 0 °C, 10 °C, 20 °C), water saturation of concrete (0 %, 30 %, 70 %, 100 %) and roughness (0, 1.5, 3.0, 4.5, 6.0 mm) on the bonding interface strength (shear strength and splitting tensile strength) were investigated through shear and splitting tests. The microstructure of the bonded interface was analysed by scanning electron microscopy at different curing temperatures and water saturation of the concrete, and an interfacial bonding mechanism was proposed. The results of the study show that the strength of the bonded interface increases gradually as the curing temperature rises. At the same curing temperature, the strength of the bonded interface decreases with increasing water saturation of the concrete and is essentially linear. The rate of strength loss of high-water-saturation specimens increases gradually as the temperature rises. When the temperature is positive, the interfacial bond strength increases and then decreases with increasing roughness, and a critical value (4.5 mm) of roughness exists that makes the bond strength reach a maximum. At negative temperatures, the interfacial bond strength increases with increasing roughness. The grey correlation analysis shows that roughness has the greatest influence on the interfacial bonding performance, followed by curing temperature and then water saturation. The interfacial shear strength and splitting tensile strength have a good linear relationship under the influence of all factors. Microscopic tests show that the polyurethane mortar body structure loosens gradually as the curing temperature decreases. As the water saturation of the concrete increases, the interface width between the polyurethane mortar and concrete shows an overall tendency to increase.

Advanced morphological characterization of DC sputtered copper thin films

In this paper, Cu thin films were successfully deposited on glass substrates using DC magnetron sputtering at varying deposition times. The deposition time was varied as 5, 9, 11 and 17[Formula: see text]min. The obtained Cu thin films were analyzed for morphology and topography using atomic force microscopy (AFM). The size of the surface structures/grains was seen to evolve with deposition time. The conventional/statistical, fractal and multifractal analyses were carried out on AFM images using existing imaging algorithms. The arithmetic roughness and interface width parameters were seen to evolve with the sputtering time. The autocorrelation and height–height correlation functions revealed that the surfaces of all the Cu thin films exhibited self-affine character, but were not mounded properties. The fractal dimensions computed using box counting and power spectral density functions revealed that larger dimensions were associated with larger surface features. The lacunarity coefficients were too small indicating that the surfaces were generally deficient in porosity and other defects. The multifractal analyses revealed that spatial roughness does not exhibit linear relationship with the deposition time. The study reveals that surface evolution and nanoscale behavior is significantly influenced by the deposition time although a linear relationship is not established.

Interfacial microstructure design and mechanical properties of the Ti–10Mo double harmonic alloy through powder metallurgy

Heterogeneous metallic materials are expected to realize the strength-toughness synergy. The interface, i.e., diffusion area, is a key factor in determining mechanical properties. In this work, Ti–10Mo chemical and structural double harmonic (CSDH) specimens with different interfacial widths and microstructures were prepared through a powder metallurgy method. All CSDH specimens exhibit similar microstructure features. From the Ti area to Mo, the feature changes in the order of blocky α-Ti grains, long acicular martensite, short acicular martensite, tiny white dot grains, and flat gray β(S) zone surrounding white β-Mo zones. However, the width of diffusion area, i.e., the interfacial width, increases with the diffusion time. The width of α′ martensite zone increases gradually to a plateau, but an ever-increase in the width of α" martensite zone. The increased interfacial width ensures high strength, meanwhile the transformation-induced plasticity occurring in the metastable α" martensite zone guarantees favorite elongation. Thus, all CSDH specimens after diffusion from 1 to 8 h display excellent mechanical properties (960–1070 MPa for σb and around 10 % for εf). The findings can help to develop new heterogeneous metallic materials with strength-toughness synergy and enrich its strengthening-toughening theory.

Dendrite operating state in directional solidification of AlCu binary system: numerical benchmark test with the OpenPhase software

A scientific benchmark test is carried out for a multi-phase-field model with double-obstacle potential by performing three-dimensional simulations of dendritic growth under directional solidification. The effects of key numerical parameters of the multi-phase-field model such as numerical resolution and interface width on the dendrite tip operating state are studied, optimal parameter values are set, and where the operating state becomes independent of varying these parameters is elaborated. Some uncertainties in the proper choice of effective interface mobility in the thin-interface limit are discussed and a pragmatic solution is adopted. The binary alloy Al-Cu with 4 at.% Cu is chosen as the material system because it has been used in many previous experimental and numerical studies to investigate dendrite morphology under directional solidification. The recently developed sharp phase-field model by Finel and colleagues is adapted to the double-obstacle potential function and included in the benchmark test. It is shown how the sharp phase-field model helps in achieving agreeable convergence with larger discretization, thereby reducing the computational cost significantly. The benchmarks are performed using the OpenPhase software.

A multiphase-field approach to small strain crystal plasticity accounting for balance equations on singular surfaces

AbstractAn implementation of the crystal plasticity theory in the context of the multiphase-field method provides a numerically efficient tracking of evolving grain boundaries, modeled as diffuse interfaces. In literature, several approaches exist for the implementation of the plastic material behavior within the diffuse interface, based on interpolation, homogenization, or the mechanical jump conditions. Among these, only the jump condition approach exhibits an intrinsic relationship to the sharp interface (SI) theory. Therefore, in the work at hand, the implementation of the crystal plasticity theory within the jump condition approach, referred to as phase-specific plastic fields approach (PSPFA), is discussed in detail. The PSPFA is compared to the interpolation approach, referred to as common plastic fields approach (CPFA), using three-dimensional benchmark simulations of a bicrystal set-up. The comparison reveals that the PSPFA and SI coincide convincingly regarding the accumulated plastic slip and the Mises stress. In contrast, a significant deviation of CPFA and SI is observed both quantitatively and qualitatively, not only within the diffuse interface region, but throughout the complete simulation domain. A variation of the interface width illustrates that this observation can be transferred to the normal components of the total strain, even for smaller interface widths. Consequently, a quantitative estimate of the plastic material behavior, which is crucial for the prediction of the dynamic behavior of grain boundaries, is only provided by the PSPFA. The application of the crystal plasticity in the context of PSPFA to more complex microstructures is illustrated with respect to a periodic honeycomb-structure and an octotuple.

Sharp interface limit of the Cahn–Hilliard reaction model for lithium-ion batteries

We propose a weak solution theory for the sharp interface limit of the Cahn–Hilliard reaction model, a variational PDE for lithium-ion batteries. An essential feature of this model is the use of Butler–Volmer kinetics for lithium-ion insertion, which arises as a Robin-type boundary condition relating the flux of the chemical potential to the reaction rate, itself a nonlinear function of the chemical potential and the ion concentration. To pass through the nonlinearity as the interface width vanishes, we introduce solution concepts at the diffuse and sharp interface level describing dynamics principally in terms of an optimal dissipation inequality. Using this functional framework and under an energy convergence hypothesis, we show that solutions of the Cahn–Hilliard reaction model converge to a Mullins–Sekerka type geometric evolution equation as the width of the transition layer vanishes.

Current reversal in polar flock at order-disorder interface.

We studied a system of polar self-propelled particles (SPPs) on a thin rectangular channel designed into three regions of order-disorder-order. The division of the three regions is made on the basis of the noise SPPs experience in the respective regions. The noise in the two wide regions is chosen lower than the critical noise of order-disorder transition and noise in the middle region or interface is higher than the critical noise. This makes the geometry of the system analogous to the Josephson junction (JJ) in solid-state physics. Keeping all other parameters fixed, we study the properties of the moving SPPs in the bulk as well as along the interface for different widths of the junction. On increasing interface width, the system shows an order-to-disorder transition from coherent moving SPPs in the whole system to the interrupted current for large interface width. Surprisingly, inside the interface, we observed the current reversal for intermediate widths of the interface. Such current reversal is due to the strong randomness present inside the interface, which makes the wall of the interface reflecting. Hence, our study gives new interesting collective properties of SPPs at the interface which can be useful to design switching devices using active agents.

Research on macro-microscopic mechanical evolution mechanism of cement-stabilized steel slag

In this paper, the chemical composition, phase composition, physical properties and expansibility of steel slag in Xinjiang, China are analyzed, and the feasibility of steel slag as pavement base material is demonstrated. At the same time, through the tests of unconfined compressive strength, X-ray diffraction, scanning electron microscope and nuclear magnetic resonance, the relationship between macroscopic strength and microstructure of cement-stabilized steel slag at different ages is discussed and compared with that of cement-stabilized macadam. The results show that the mechanical properties of steel slag aged more than one year can fully meet the requirements of relevant specifications for all kinds of pavement base. Compared with cement-stabilized macadam, the compressive strength of cement-stabilized steel slag at the age of 7 d, 14 d and 28 d increased by 15.4%, 22.0% and 23.7%, respectively. Due to hydration and pozzolanic action, the C–S–H content in the interfacial transition zone of cement-stabilized steel slag is higher, while the contents of Ca(OH)2 and AFt are lower. Due to the internal curing effect of steel slag, the interfacial transition zone width of cement-stabilized steel slag at the age of 7 d and 28 d decreased by 9.4% and 31.0% respectively compared with cement-stabilized macadam; with the increase of curing time, the adsorption porosity of cement-stabilized steel slag increased, while the amount of seepage pore and migration pore decreased significantly, and the pore span and total porosity decreased by 47.7% and 7.29%, respectively.

Long term durability assessment of self-compacting concrete made with crushed recycled glass and metakaolin

Sustainable production in construction industry can only be possible through a proper management and conservation of limited natural resources such as fine aggregates. This challenge can be tackled by efficient utilization of discarded waste material such as glass in production of sustainable concrete. This paper investigates the use of crushed recycled glass (CRG) and metakaolin (MK) in development of durable self-compacting concrete (SCC). Four groups of SCC mixtures were prepared using different proportions of CRG (0–50%), while keeping MK concentration equal to 0%, 4%, 8% and 12%. Durability performance of SCC was accessed using water absorption, sorptivity, chloride ion permeability, drying shrinkage, water penetrability under pressure and alkali-silica reaction (ASR) tests. As the CRG content increased, group 4 (having 12 % MK) was most efficient in improving drying shrinkage and pressurized water penetration results; whereas Group 1 (0% MK mixtures) exhibited a minimal change. Raising CRG content in the mix resulted in decrease of water absorption and chloride ion penetration for all groups with group 4 exhibiting maximum reduction. ASR testing revealed that incorporating glass at a higher concentration (40% and 50%) resulted in excessive expansion (more than prescribed limit of 0.1%), which can be suppressed by partially substituting cement with MK. FE-SEM and TGA analysis were carried out to understand the mechanism behind these changes, which revealed that the secondary hydration products formed by addition of MK in concrete can densify the pore structure and refine CRG particle-cement paste interfacial micro-crack width (was evident from FE-SEM micrographs), thus improving the durability of concrete. Indeed, simultaneous incorporation of CRG and MK proved to be advantageous for development of green SCC.

A thermodynamically consistent non-isothermal phase-field model for selective laser sintering

Selective laser sintering (SLS) additive manufacturing possesses the characteristics of extremely non-uniform temperature distribution and high temperature gradient, which are unmanageable by the traditional isothermal models. In this work, we propose a thermodynamically consistent non-isothermal phase-field model (PFM) to investigate the microstructure evolution during SLS process with the full consideration of temperature gradient effect. The model is derived from a thermodynamic framework which invokes the microforce theory and Coleman–Noll procedure. The temperature-dependent parameters in the free energy formulation are determined by the experimentally measurable surface energy and grain boundary energy with a given interface width. Benchmark simulations of sintering two particles under temperature gradient indicate that the grain boundary has the trend to migrate to the higher temperature region, which is further verified by molecular dynamics simulations. This phenomenon cannot be captured by the traditional isothermal PFM. Grain boundary migrations can also be driven by curvature for two unequally-sized particles. Simulations on SLS of powder bed show the dependence of microstructure evolution and final porosity on the laser power and scanning speed. The developed non-isothermal PFM could be a practicable toolkit for the microstructure simulation of SLS process.

Fast crystal growth of ice VII owing to the decoupling of translational and rotational ordering

Despite the abundance of water’s crystalline polymorphs, the growth mechanisms of most ice forms remain poorly understood. This study applies extensive molecular dynamics (MD) simulations to examine the growth of ice VII, revealing a fast growth rate comparable to pure metals while maintaining robust hydrogen-bond networks. The results from an unsupervised machine learning applied to identify local structure suggest that the surface of ice VII consistently exhibits a body-centered cubic (bcc) plastic ice layer, indicating the decoupling of translational and rotational orderings. The study also uncovers the ultrafast growth rate of pure plastic ice, indicating that orientational disorder in the crystal structure may be associated with faster kinetics. Additionally, we discuss the impacts of interfacial plastic layer width and surface roughness on growth mode.

Computational modeling of laser welding for aluminum–copper joints using a circular strategy

Dissimilar metal welding poses a significant challenge for researchers in the welding and materials science communities due to the different properties of the metals involved. In this study, we present a novel approach for determining the optimal processing parameters for continuous laser welding (CLW) of dissimilar metals, specifically aluminum and copper, using a circular strategy. The approach utilizes computational fluid dynamics (CFD) simulations to model the welding process and predict joint quality. We validated a CFD-based numerical model for predicting the melt-pool shape across a range of laser power and circular welding speed values. Additionally, we developed artificial neural network (ANN) models that can predict melt pool interface width, penetration depth, and copper concentration for any combination of processing conditions. Using surrogate modeling, we identified the optimal values of laser power and welding speed that result in the highest quality joint. Our results showed that the optimal processing conditions were a laser power of 2950W and a circular speed of 55 mm/s, which resulted in a high-quality Al–Cu joint with maximum shear strength of 2200 N. Microstructural analysis and tensile-shear strength testing confirmed that the optimal conditions resulted in a low degree of intermixing and the absence of large intermetallic compounds (IMCs) in the weld seam. Overall, study offers a valuable contribution to the welding and materials science communities by presenting a novel approach to address a common challenge in dissimilar metal welding. Our approach can be applied to other types of dissimilar metal welding and may inform the development of new welding techniques in the future.

Interfacial electronic structure modulated magnetic properties in Ta/CoFeB/Ta multilayers

Thinfilm heterostructure Ta/CoFeB/TaOx can exhibit chiral magnetic textures such as skyrmions as well as spin-orbit torque induced zero field magnetization switching, which offers great promise for next-generation information storage technologies. Here, we provide a strong correlation between the structural and magnetic properties in as-deposited and annealed Ta (1 nm)/ CoFeB (1.5 nm)/ TaOx (1 nm) trilayer and Ta (1 nm)/ CoFeB (1.5 nm)/ Ta (t)/ CoFeB (1.5 nm)/ TaOx (1 nm)] multilayered stack with t = 0.5, 1 nm. Interestingly, x-ray reflectivity results indicate improvement in the interface quality post annealing up to 300 °C. While the thinner Ta spacer layer (0.5 nm) in the stack causes the formation of smaller interface width, the thicker Ta spacer (1 nm) results in relatively larger interface width. Annealing results in the enhancement of saturation magnetization (Ms) and uniaxial magnetic anisotropy (UMA) and the extent of variation is mostly determined by thickness of the spacer Ta layer. Magneto-optical Kerr effect measurement suggests the existence of strong two-fold UMA in the film stack with Ta spacer layer 0.5 nm, however, its strength diminishes as the Ta spacer layer thickness is increased to 1.0 nm. Furthermore, the in-depth chemical/electronic investigations using x-ray photoelectron spectroscopy technique reveal the formation of additional chemical states such as TaB and TaOB at the interfaces. Remarkably, Boron diffusion and likely oxygen migration from the Fe-oxide/Co-oxide in CoFeB to neighboring Ta layers improves the metallic nature of Fe and Co due to annealing. Note that the thicker Ta spacer has a significant impact on the chemical transformation at the interface in comparison to that of thinner Ta spacer layer. Overall, in these Ta/CoFeB multilayered stacks, the thickness of the Ta spacer layer and annealing temperature play a crucial role in controlling interface quality that eventually governs the magnetic characteristics. These results provide new insight into the interfacial electronic structure modifications which are essential for controlling DMI and stabilization of skyrmions in Ta/CoFeB multilayers for future spintronic device applications.