Metal Bond Research Articles

Atom Probe Tomography: a Local Probe for Chemical Bonds in Solids.

Atom probe tomography is frequently employed to characterize the elemental distribution in solids with atomic resolution. Here the potential of this technique to locally probe chemical bonds is reviewed and discussed. Two processes characterize the bond rupture in laser-assisted field emission, the probability of molecular ions (PMI), i.e., the probability that molecular ions are evaporated instead of single (atomic) ions, and the probability of multiple events (PME), i.e., the correlated field-evaporation of more than a single fragment upon laser- or voltage pulse excitation. Here it is demonstrated that one can clearly distinguish solids with metallic, covalent, and metavalent bonds based on their bond rupture, i.e., their PME and PMI values. These findings open new avenues in understanding and designing advanced materials, since they allow a quantification of bonds in solids on a nanometer scale, as will be shown for several examples. These possibilities would even justify calling the present approach bonding probe tomography (BPT).

Study on the occurrence characteristics of arsenic in copper matte

The occurrence characteristics of arsenic in matte phase are unclear, which leads to the current treatment technology not being able to remove arsenic from matte phase significantly, thus causing a large amount of arsenic to affect smelting links such as copper converting and electrolytic refining. This paper uses instrumental analysis such as XRD, SEM-EDS, MLA and chemical analysis methods such as chemical phase extraction to comprehensively analyze the occurrence characteristics of arsenic in matte phase. The results show that the occurrence states of arsenic in matte are mainly arsenic sulfide, arsenic oxide, arsenate and residual arsenic. Most of the arsenic is in residual state in matte; arsenic in matte is extremely stable and difficult to exchange with the outside world; in high-grade matte, the arsenic content is relatively high. The main occurrence state of arsenic is copper-based complex alloy compounds, in which the arsenic content is about 1-10%. Since the metal bond between Cu-As is extremely stable, it is difficult to separate arsenic from it, which is also the key to the difficulty in completely removing arsenic from matte.

Evaluation of the Bond Strengths Between Dental Ceramics and Co-Cr Frameworks Made with Digital and Conventional Techniques.

Evaluate the influence of different Co-Cr framework manufacturing techniques on the bond strength between metal and two types of veneering ceramic with and without a metal primer. 72 metal specimens were fabricated using the same Co-Cr alloy (Keramit NP; Nobil Metal) with three different techniques: ingots for casting (Keramit NP); disks for CAD/CAM milling (Synergy Drive Keramit NP); and powder for SLM (Keramit NP-S). Each of the 24-specimen groups, was divided into two subgroups, according to the application, or not, of Nobil Metal Bonding (NMB) (Nobil Metal). Two different veneering ceramic systems were used: Ceramco iC (Dentsply) and Noritake super porcelain EX-3 (Noritake). The bond strength of the metal-ceramic system was evaluated using the three-point bending test and the modality of failure with SEM analysis. Three-way Anova with interactions was used to evaluate the influence of the metal production process, the presence or absence of the bonding agent and the type of veneering ceramic on ceramic-metal adhesion. All specimens exceeded the minimum bond strength of 25 MPa required by ISO Standard 9693 - 1:2012. The highest values of adhesion were registered for specimens manufactured with casted metal/Noritake veneering ceramic (40.59 ± 7.30 MPa). The lowest values were registered for specimens manufactured with CAD/CAM metal/NMB/Ceramco iC veneering ceramic (29.47 ± 3.38 MPa). The fabrication method and the type of veneering ceramic had a significant influence on the mean bond strength. The application of the NMB did not show an influence on bond strength.

Green tea (Camellia sinensis L.) potential to liver of hyperuricemia rats (Rattus norvegicus) fed with high purine diet

Uric acid is produced in tissues containing xanthine oxidases, like the small intestine and liver, as involved in the purine metabolism of adenine and guanine. High uric acid levels cause damage to cell membranes due to the lipid peroxidase chain reaction. Foods containing high purines will activate the xanthine oxidase (XOD), causing an increase in free radicals. Free radicals attack polyunsaturated fatty acids (PUFA) by forming lipid peroxides. PUFA molecules contain multiple double bonds, which make them susceptible to oxidation by reactive oxygen species (ROS), such as free radicals. PUFA will be broken into simple compounds such as pentane, ethane, and aldehydes, leading to malondialdehyde (MDA) formation. High MDA levels illustrate the process of cell membrane oxidation leading to cell membrane damage. Hyperuricemia is often treated using synthetic drugs such as allopurinol; however, it can cause side effects. Some people will choose medicinal plants with minimal side effects. Green tea (Camellia sinensis L.) contains many polyphenol antioxidants, especially flavonoids, which also have a strong antioxidant effect by exerting multiple mechanisms such as inhibiting several enzymes, including antiphospholipid peroxidase, free radical scavengers, metal bonds, and xanthine oxidase (XOD). Statistical analysis results proved that green tea with a dose of 600 mg/kg BW could decrease the level of MDA in the liver by 84.87% (p 0.01) and reduce the activity of XOD by 35.36% (p 0.01). Taken together, green tea can improve liver histopathology.

Interfacial microstructure evolution and mechanical characterization of brazed Al2O3 joints with Ni‒Ti interlayer: An experimental and theoretical approach

Reliable brazing joints of Al2O3 ceramics were obtained using an active Ni‒Ti interlayer under vacuum conditions. The interfacial microstructure and mechanical properties of the joints were studied. The structural, electronic, and elastic properties of the primary interfacial reaction phases were determined using first–principles calculations. After brazing at 1320 °C for 30 min, Ni2Ti4O layer and columnar AlNi2Ti formed at the interface adjacent to the Al2O3 substrate. With increasing brazing temperature between 1300 °C and 1380 °C, Ni2Ti4O layer thickened gradually, and the AlNi2Ti became increasingly longer. As brazing temperature reached 1400 °C, TiO was formed at the interface, and the Ni2Ti4O content decreased significantly; moreover, bulk AlNi2Ti and TiNi3 were distributed in the brazing seam. The highest shear strength of 129 MPa was achieved when brazed at 1350 °C for 30 min. According to the first–principles calculations, Ni2Ti4O is more readily formed than AlNi2Ti, whereas AlNi2Ti exhibits greater stability than Ni2Ti4O. Both AlNi2Ti and Ni2Ti4O possess metallic bonds, contributing to the adhesion of the filler metal to the Al2O3 substrates. The calculated modulus and Poisson’s ratio indicate that both AlNi2Ti and Ni2Ti4O exhibit ductile characteristics, which assist in relieving residual stress within the joint.

Electron work function guided tailoring of (W4-x, Mx)C4 /doped Ni matrix interfacial bonding: Insights from first-principles calculations

Heavy tungsten carbide (WC) may cause inhomogeneous distributions in WC-metal matrix composite hardfacing overlays, thus negatively affecting its performance as reinforcement. WC can be lightened by partially substituting W with lighter metals, e.g., Mo and Cr, while maintaining its strength. However, the bonding between modified WC and matrix metals such as nickel (a typical metal-matrix for overlays) is uncertain. This article reports a study on the interfacial bonding between (W4-x, Mx)C4 (M=Mo or Cr) and Ni matrix via first-principle calculations. Different atomic interactions i.e., metal-metal and metal-carbon interactions, at the interface were studied to understand the interfacial bonding through analyses of electron work function (EWF), electron localization function, electronic density of states, bond order, and net charge. It was demonstrated that the lighter (W4-x, Mx)C4 carbides exhibit strong bonding with Ni, comparable to or even stronger than that of WC/Ni interface, and the interfacial bonding includes covalent, ionic and metallic bond components. It is demonstrated that the interfacial bonding can be tuned by doping elements in the Ni matrix with different EWFs, e.g., Mn, Cu, Au, Pt, and Se. Efforts have been made to verify a hypothesis that EWF is an indicator, which can be used to guide selecting effective dopants for tailoring the interfacial bond strength.

Prediction of the thermal-physical properties of amorphous nickel alloys Ni2B, Ni44Nb56, Ni62Nb38 according to component data

The replacement of traditional materials with amorphous alloys and the operation of products made from them are determined by the structural, temporal and temperature stability of disordered environments. In particular, the thermal stability of an amorphous alloy directly depends on its thermophysical characteristics. Therefore, the article demonstrates the applicability of the rule of mixing components and the use of their data on thermophysical properties in the crystalline state to evaluate similar characteristics of alloys from the metal – metalloid and transition metal – transition metal groups in the amorphous phase. It has been established that for the transition metal – transition metal group, the assessment of the heat capacity of amorphous nickel alloys gives a better approximation to the experimentally established values than for an alloy from the metal – metalloid group. The reasons for the discrepancy between the assessment and experimental data for an alloy from the metal – metalloid group are possibly the covalency of the atomic bonds in contrast to the metallic bond for alloys from the transition metal – transition metal group, the smaller size of the metalloid atoms, its greater mobility and the effect on the refinement of alloy grains. The possibility of an amorphous alloy inheriting some properties of one of the components is indicated, which requires experimental verification.

The influence of different vacancies on Zr(0001)/SiC close-packed interface performance: A first-principles study

The first-principles were employed to investigate the structure, adhesion, and tensile properties of the Zr(0001)/SiC close-packed interface with different vacancies. From the perspective of vacancy formation energy, SiC coating is beneficial for enhancing the irradiation resistance of Zr cladding. When vacancies are present, except for the Zr2 and Zr3 vacancies, introducing other vacancies reduces the stability of Zr/SiC interfaces. The C-terminated interface is more stable than the Si-terminated interface. Through electronic structure analysis, vacancies at the interface primarily reduce the bonds between Zr and SiC, decreasing the interface stability. Vacancies on the side of SiC indirectly alter the strength or quantity of covalent (bonding or anti-bonding) and ionic bonds at the interface, thus intricately lowering the interface stability. In tensile tests, the cleavage of all interfaces with vacancies still occurs on the side of Zr. Vacancies on the SiC side partly lead to increased electrons between Zr1-Zr2 or Zr2-Zr3, strengthening the metallic bonds and enhancing the interface's ideal strength and ductility. The present study offers a novel perspective from the standpoint of bonding mechanisms, providing good insights into the effects of different vacancies on the performance of Zr/SiC interfaces.

Study of structural, magnetic, and physical properties in nano cobalt ferrite by computational analysis

Using the DFT+U method, we investigated the structural, magnetic, electronic, mechanical, thermal, optical, thermoelectric, and thermodynamic properties of the CoFe2O4 system. The GGA approximation was employed to calculate the exchange–correlation potential. The CoFe2O4 has a metallic bond and is ductile, as determined by Poisson’s and Pugh’s ratio mathematical calculations. Transport properties such as the figure of merit, thermal (k/τ) and electrical (σ/τ) conductivities, power factor, and Seebeck coefficient were computed to explain the thermal behavior of this spinel. Additionally, optical parameters like energy loss L(ω), absorption coefficient α(ω), dielectric constants ε(ω), optical conductivity σ(ω), reflectivity R(ω), extinction coefficient k(ω), and refractive index n(ω) are investigated. Lastly, we study how the magnetic phase transitions, magnetization, critical temperature, and specific heat capacity of this material are affected by an external magnetic field at constant pressure. Around the critical temperature, magnetic entropy and relative cooling capacity for various external magnetic fields are obtained.

Assessing thermal resistance in fusion bond layers of 3D heterogeneous electronics packaging

We investigated thermal management challenges in semiconductor devices that use fusion bonding, with a focus on measuring the thermal resistance of the bonded interface. Starting with two fusion-bonded silicon wafers, we thinned the top wafer to below 100 μm and used frequency domain thermoreflectance to measure the effective thermal boundary resistance of the fusion bond. We established the measurement uncertainty with a multilayer thermal diffusion model, considering the effects of the top Si layer thickness and laser spot size. The thermal boundary resistance was measured to be 0.2 and 0.5 m2K/MW for two types of bonded wafers, with total SiO2 film thicknesses of 200 and 470 nm at the fusion bond layer, respectively. We also created defects at the interface and imaged these defects with the thermal phase response at specific frequencies chosen according to a thermal model. The method described can be applied to other types of wafer-to-wafer or die-to-die bonding including direct, polymeric, and metallic bonds.

The Effect of Shot Blasting Abrasive Particles on the Microstructure of Thermal Barrier Coatings Containing Ni-Based Superalloy

Grit particles remaining on the substrate surface after grit blasting are generally considered to impair the thermal performance of thermal barrier coatings (TBCs). However, the specific mechanisms by which these particles degrade the multilayer structure of TBCs during thermal cycling have not yet been fully elucidated. In this study, the superalloy substrate was grit-blasted using various processing parameters, followed by the deposition of thermal barrier coatings (TBCs) consisting of a metallic bond coat (BC) and a ceramic top coat (TC). After thermal shock tests, local thinning or discontinuities in the thermally grown oxide (TGO) layer were observed in TBCs where large grit particles were embedded at the BC/substrate interface. Moreover, cracks originated at the concave positions of the TGO layer and propagated vertically towards BC; these cracks may be associated with additional stress imposed by the foreign grit particles during thermal cycling. At the BC/substrate interface, crack origins were observed in the vicinity of large grit particles (~50 μm).

No-impact trajectory design and fabrication of surface structured CBN grinding wheel by laser cladding remelting method

The structured grinding wheels have a specially designed macro or microstructure on the surface, with a relatively low average grinding force and temperature in the cutting zone and more space for chips and coolant. Most traditional grinding wheel fabrication methods, such as electroplating, sintering, and brazing, have the problems of poor abrasive grain holding strength, random abrasive distribution, or thermal deformation of the substrate. To address this, laser cladding remelting technology is introduced to fabricate the structured CBN grinding wheel. A no-impact trajectory was designed on the substrate of the grinding wheel, which can reduce the fluid friction in the channel and increase the fluid pressure at the outlet. The temperature and velocity fields of the grinding process were simulated to verify the feasibility of the designed structure theoretically. The optimal process parameters for the bonding among the metal bond, the abrasive grains, and the substrate were determined by orthogonal and full-scale factorial experiments. The chemical metallurgical reactions between CBN grain and metal bond, as well as between the metal bond and substrate, were formed, increasing the holding force of CBN grains. The method can realize the fabrication of high-strength and long-life structured grinding wheels with an orderly arrangement of abrasive grains. The micro-mechanism of fabrication was analyzed using element distribution measurement and XRD analysis.

Chemical-bonding and lattice-deformation mechanisms unifying the stability and diffusion trends of hydrogen in TiN and AlN polymorphs

The continuous development of hydrogen-permeation barriers (HPB) based on metal nitrides highly desires a generic unification of the key thermodynamic and kinetic mechanisms therein. This work employs first-principles calculations to study the stability and diffusion trends of H impurity in the rock-salt, wurtzite, and sphalerite phases of the prototypical TiN and AlN. The formation energies (Ef) of H at various interstitial and vacant sites in these nitrides are calculated, and the underlying chemical-bonding and lattice-deformation mechanisms are self-consistently revealed by the systematic structual, energetic, and electronic-structure analyses. This leads to the discovery of a generic volcanic trend of Ef in terms of the electron number on H (QH), which well portrays how the covalent-ionic H–N and H–metal bondings determine its stability in different atomistic environments. Then, the kinetic properties (e.g., potential barriers, diffusion coefficients, and isotope effects) of interstitial H in these nitrides are calculated, where the volcanic Ef–QH relationship is applied to better understand the joint contributions of chemical bonding and lattice deformation. Finally, the revealed mechanisms and volcanic Ef–QH relationship are generalized to successfully describe the behaviors of H in some important grain boundaries of c-TiN and c-AlN, including the Σ3{112}〈110〉 twin frequently observed in c-TiN and the Σ5{210}〈001〉 twin prototypical to many rock-salt materials. The widely varying hydrogen permeabilities measured in experiment on many nitride coatings are successfully explained, inspiring more useful chemical principles to guide the design of HPB coatings facing harsh environments with long-term reliability.

Cu-bearing HHCCI interface combined with first principles calculation and corrosive wear resistance

The corrosive wear resistance of copper-bearing HHCCI was tested through experiments and HRTEM, combined with first-principles calculations to study the atomic structure, interface fracture work, thermodynamic stability, electronic structure and bonding structure of six Fe3Cr4C3(01 1‾ 0)/γ-Fe(101) interface models with different termination methods. The HRTEM results show that the interface formed by (01 1‾ 0) of M7C3-type carbide and (101) of the austenite matrix is a coherent interface. The first principles calculation results show that the interface formed by the Fe3Cr4C3(01 1‾ 0)-Cr termination model and the γ-Fe (101)-2 termination model has the highest interface bonding strength. The Fe-end/7Fe-2 interface model is the most stable. Both the interfacial chemical energy and the interfacial elastic energy will affect the overall thermodynamic stability of the Fe3Cr4C3(01 1‾ 0)/γ-Fe (101) interface. The fracture work of Fe3Cr4C3(01 1‾ 0) and γ-Fe (101) is greater than the corresponding interface adhesion work. Moreover, the fracture work on each terminal end of M7C3 along the (01 1‾ 0) surface is higher than that on each terminal end of γ-Fe along the (101) surface. The failure of HHCCI during corrosive wear may mainly occur in the interface area or the side close to the γ-Fe matrix. The chemical bonds in the Fe-end/7Fe interface are mainly Fe-Fe metal bonds, Fe-Cr metal bonds and some Fe-C polar covalent bonds. The chemical bonds in the Cr-end/7Fe interface are mainly Cr-Fe metal bonds and some Cr-C polar covalent bonds. The chemical bonds in the C-end/7Fe interface are mainly composed of Cr-Fe metal bonds, C-Fe polar covalent bonds and part of C-Cr polar covalent bonds, as a result, each interface exhibits different corrosive wear resistance potentials.

Structural, vibrational, and electrical study of the topological insulator PbBi2Te4 at high pressure

We report a joint experimental and theoretical study of the structural, vibrational, and electric properties of the topological insulator PbBi2Te4 under compression through X-ray diffraction, Raman scattering, and electrical measurements at high pressure, which are complemented with theoretical calculations that include the analysis of the topological electron density. The internal polyhedral compressibility of the rhombohedral phase, the behavior of its Raman-active modes, the electrical behavior, and the nature of its different bonds under compression are discussed and compared with their parent binary compounds and with related ternary materials. Interestingly, PbBi2Te4 retains its topological insulating properties as far as the rhombohedral tetradymite-like phase is retained under compression, unlike other tetradymite-like compounds. In addition, PbBi2Te4 undergoes an unconventional reversible pressure-induced decomposition into the high-pressure phases of its parent binary compounds (PbTe and Bi2Te3) above 8 GPa. Finally, we discuss that the intralayer bonds in the tetradymite-like structure of PbBi2Te4 are electron-deficient multicenter bonds; i.e. bonds of the same kind as those present in its parent binary compounds, in related chalcogenides, such as SnSb2Te4, and in general in chalcogenide-based phase change materials. These unconventional bonds are intermediate between covalent and metallic bonds and provide exceptional properties to the materials.

Gallocyanine-mediated non-covalent functionalization and exfoliation of h-BN for efficient anticorrosion reinforcement of waterborne epoxy coating

Hexagonal boron nitride (h-BN) is commonly used to enhance the anti-corrosion of organic coatings due to its excellent barrier properties, dielectricity and mechanical robustness. However, the bulky h-BN tends to create poor dispersibility and interfacial compatibility problems with the resin matrix, leading to coating cracking and failure. H-BN nanosheets exfoliated by conventional methods only provide passive barrier effect with coatings at the initial stage of corrosion. Herein, we used a mussel-inspired non-covalent functionalization strategy, using the catechol groups and heteroaromatic ring structure of gallocyanine to achieve the functionalization and exfoliation of h-BN through ball milling, and obtained ultra-thin h-BN@G nanosheets. Remarkably, spare gallocyanine can further suppress the erosion, whose inhibition efficiency is 95.48 % at the concentration of 100 mg/L in 1 M HCl within 9 h. Typically, after 105 days of immersion in 3.5 wt% NaCl solution, the low-frequency impedance of h-BN@G/WEP coating is still as high as 1.45 × 109 Ω cm2, which is two orders of magnitude higher than that of the pure coating. The superior long-term anti-corrosion capacity can be ascribed to the triple protection of enhanced shielding property of desirable-exfoliated h-BN, passivation films adsorbed on the metal and coordination bonds formed between gallocyanine and the iron to resist the active corrosion. Our work offers an innovative idea for the functionalization and exfoliation of other lamellar materials, which can be applied to the implementation of long-lasting anti-corrosion coatings.

Semiconductor-metal transition in TlPbF3 under isotropic pressure and its impact on optical, elastic and mechanical properties: a DFT computation with HSE06

This research aims to comprehensively evaluate the structure, elasticity, mechanics, anisotropy, electrical properties, and optical attributes of TlPbF3 at pressures from 0 to 60 GPa. A cubic structure of the material remains same without any phase changes, but there is a reduction in the lattice parameters. The material is determined to be mechanically secure by doing calculations on a variety of mechanical and elastic characteristics, including bulk, shear, and Young’s modulus, stiff, and not particularly flexible. It also shows a significant resistance to shear force. The material’s ability to withstand high pressures, its metallic bond nature, and ductility have been shown by the Kleinman’s parameter, Poisson’s ratio, Cauchy pressure, and Pugh ratio. Anisotropy can be confirmed by activating specific anisotropy factors. When we consider the electronic band structure, we observe a transition from a broad gap in the band (3.719 eV) comparable with a small band distance (0.65 eV), and converts to a metal (0 eV). To explore this, we have estimated the total, partial and elemental partial density of states. Additionally, we have computed the real and imaginary functions of dielectric, absorption factor, refractive index, extinction coefficient, loss function, reflectivity and real/imaginary conductivity to assess the material’s applicability. As pressure is applied, the static values of ε1(ω) and n(ω) increase. This material is also well-suited for optoelectronic devices due to its high conductivity, reflectivity, absorption, and refractive index.

Dressing Mechanism and Evaluations of Grinding Performance with Porous cBN Grinding Wheels

Cubic boron nitride (cBN) grinding wheels play a pivotal role in precision machining, serving as indispensable tools for achieving exceptional surface quality. Ensuring the sharpness of cBN grains and optimizing the grinding wheel's chip storage capacity are critical factors. This paper presents a study on the metal-bonded segments and single cBN grain samples using the vacuum sintering method. It investigates the impact of blasting parameters—specifically silicon carbide (SiC) abrasive size, blasting distance, and blasting time—on the erosive wear characteristics of both the metal bond and abrasive. The findings indicate that the abrasive size and blasting distance significantly affect the erosive wear performance of the metal bond. Following a comprehensive analysis of the material removal rate of the metal bond and the erosive wear condition of cBN grains, optimal parameters for the working layer are determined: a blasting distance of 60 mm, a blasting time of 15 s, and SiC particle size of 100#. Furthermore, an advanced simulation model investigates the dressing process of abrasive blasting, revealing that the metal bond effectively inhibits crack propagation within cBN abrasive grains, thereby enhancing fracture toughness and impact resistance. Additionally, a comparative analysis is conducted between the grinding performance of porous cBN grinding wheels and vitrified cBN grinding wheels. The results demonstrate that using porous cBN grinding wheels significantly reduces grinding force, temperature, and chip adhesion, thereby enhancing the surface quality of the workpiece.

Expanding Lightweight Design Potential by Hybrid Joining of Aluminum Sheets with Aluminum Casting Through Compound Sand Casting and Induction Heating

Combining light metals like aluminum to produce lightweight structures offers a high weight‐saving and contributes to a circular economy in automotive car body construction. Compound casting is a promising process for producing car body parts. Difficulties arise in creating metallic continuity between insert and casting. Insert coatings are used to remove the oxide layer and thereby improve the wettability of the melt. This study uses a hybrid joining method to improve the metallic bond between insert and casting. Induction heating differently influences the strength properties of age‐ and nonage‐hardenable inserts. Compression shear tests characterize the metallic bond strength. Microscopic images show the influence of the process variables on the compound quality. Reproducible sound metallic bonding with low scattering is achieved by enhancing the compound casting process through induction and no insert coating. Cast wall thicknesses down to 4 mm contribute to further lightweight potential as they have the same strength level as the reference sample. A decisive factor is the insert temperature in the compound zone. Thereby, insert preheating conditions play a crucial role. Additional heat treatment of hardenable compounds leads to a further increase in metallic bond strength.

Half-metallization Atom-Fingerprints Achieved at Ultrafast Oxygen-Evaporated Pyrochlores for Acidic Water Oxidation.

The stability and catalytic activity of acidic oxygen evolution reaction (OER) are strongly determined by the coordination states and spatial symmetry among metal sites at catalysts. Herein, an ultrafast oxygen evaporation technology to rapidly soften the intrinsic covalent bonds using ultrahigh electrical pulses is suggested, in which prospective charged excited states at this extreme avalanche condition can generate a strong electron-phonon coupling to rapidly evaporate some coordinated oxygen (O) atoms, finally leading to a controllable half-metallization feature. Simultaneously, the relative metal (M) site arrays can be orderly locked to delineate some intriguing atom-fingerprints at pyrochlore catalysts, where the coexistence of metallic bonds (M─M) and covalent bonds (M─O) at this symmetry-breaking configuration can partially restrain crystal field effect to generate a particular high-spin occupied state. This half-metallization catalyst can effectively optimize the spin-related reaction kinetics in acidic OER, giving rise to 10.3 times (at 188mV overpotential) reactive activity than pristine pyrochlores. This work provides a new understanding of half-metallization atom-fingerprints at catalyst surfaces to accelerate acidic water oxidation.