Grain Growth Research Articles

Er2O3 doped ZnO–Cr2O3-based varistors with high voltage gradient

ZnO varistors are widely used in modern intelligent electrical equipment, and the preparation of miniaturized varistors with high voltage gradient has become a top priority. This work investigated the preparation of high voltage gradient ZnO–Cr2O3-based varistors doped with Er2O3 and analyzed the relationship between their microstructure and electrical properties. As the doping amount of Er2O3 increases from 0.00 to 0.75 mol%, Er2O3 phase obviously dissolving element Co distributed at the trigeminal grain boundaries increases, leading to the grain size d decreases from 3.16 to 1.70 μm, the nonlinear coefficient α increases from 6.22 to 50.48, the voltage gradient E1mA increases from 428.37 to 1616.76 V/mm, and the leakage current density JL decreases from 375.75 to 0.79 μA/cm2, achieving optimal comprehensive electrical performance of the sample with Er2O3 doping of 0.75 mol%, for which, the residual voltage ratios K reaches the minimum value of 1.14 under the impulse current density Jp of 63.7 A/cm2. When the doping amount of Er2O3 further increases to 1.00 mol%, the excessive Er2O3 phase aggregates at the trigeminal grain boundaries and distributes unevenly, leading to the growth of ZnO grains and performance deterioration of the samples. The ZnO–Cr2O3-based varistors have the advantages of much easier doping, and there is no dopant volatilization during the sintering process. This research provides an important reference for the development of high-performance, miniaturized ZnO–Cr2O3-based varistors.

Role of layer arrangement in microstructure and corrosion behavior for 78-mm thick-plate 316L stainless steel fabricated via narrow gap laser wire filling welding

Controlling repeated thermal cycling is one of the key mechanisms to design microstructures in the interlayer regions for narrow gap laser wire filling welding (NGLWFW) of austenite stainless steels. Herein, the optimization of process parameters for individual layers is tailored to customize the molten pool morphology during the NGLWFW process, facilitating precise control over the microstructure and, consequently, enhancing both mechanical properties and corrosion resistance of the joint. The results showed that the molten pool morphology acquired by simulation are obviously diverse from the bottom zone (BZ), middle zone (MZ) to upper zone (UZ) of the welded joint ascribed to the high heat accumulation effect, leading to the variation of microstructure. At BZ, the combination of smaller grain size and reduced dendrite spacing reduce the number of corrosion sites and promote the formation of a denser and more uniform corrosion product layer. Additionally, the diverse grain orientation, characterized by lower texture strength, facilitated a more uniform distribution of elements. Furthermore, the significantly higher content of δ-ferrite showing smallish shape disrupted the directional growth of austenite columnar grains, contributing to the excellent corrosion resistance observed at the BZ.

Densification mechanism and thermal shock resistance improvement of MgF2‐doped Y2O3 ceramics

AbstractThis paper aims to improve the density and thermal shock resistance of Y2O3 ceramics for the preparation of ultra‐pure high‐temperature alloy crucible materials. The doping effect of MgF2 content on the densification behavior, physical properties, and thermal shock resistance of Y2O3 ceramics was systematically investigated in this paper. The results suggested that the presence of MgF2 greatly promoted the growth of Y2O3 grains and the transformation of the pore structure by liquid‐phase sintering. And the mechanical properties of the MgF2‐doped Y2O3 ceramics were significantly improved. Besides, the marked improvement in the thermal shock resistance of MgF2‐doped Y2O3 ceramics was attributed to the synergistic action resulting from the growth of grain size and the enhancement of the crack deflection effect. In particular, the relative density of Y2O3 ceramics doped with 1.5 wt% MgF2 reached 96.4% and the residual flexural strength ratio after thermal shock achieved 45.0%, showing an excellent application prospect.

The effect of Fe2O3 doping on a Pt/Co3O4 catalyst for CO oxidation: Improvement of thermal stability and catalytic activity

Although Pt/Co3O4 is an active catalyst for CO oxidation, its low thermal stability may impede its application. The thermal stability and catalytic performance of Pt/Co3O4 were considerably enhanced by Fe2O3 doping. Fe2O3 doping stabilized the mesostructured material during the high-temperature treatment, and the Fe2O3-doped samples retained a larger specific surface area. The characterization results revealed that Fe2O3 doping inhibited catalyst crystallization and decomposition and the growth of catalyst grains during high-temperature calcination. The Fe2O3 doping reduced the Co-O bond strength in the surface Co3O4 lattice, increased the Co3+ ratio, and generated highly active surface oxygen species. Fe2O3 doping also facilitates CO2 desorption, which improves CO adsorption and oxidation. SO2 and NO impede CO oxidation on Pt/Fe2O3/Co3O4. This negative impact was caused by the inert species formed when SO2 or NO reacted with O2 on the catalyst, such as SO42-, HSO4-, or nitrate species, which covered the active sites.

Unveiling the recrystallization mechanism and kinetics parameters in cold-rolled dual-phase stainless steel using differential scanning calorimetry

The present work aims to assess the Recrystallization mechanism and Kinetics parameters in Cold-Rolled Dual-Phase stainless steel. For this purpose, Differential Scanning Calorimetry was used over a range of 5–20 K/mn of heating rate, to identify the classical kinetic parameters such as recrystallization temperature, activation energy, and growth mechanism following 90 % reduction in thickness. The findings revealed that the recrystallization temperature increased with rising heating rates within the range [706.8–732] for the ferrite phase, as well as [1282.0–1360.3] K for the austenite phase. The estimated activation energies for ferrite and austenite recrystallization fell within the range of [207.2 ± 1.4–220.1 ± 2.5] kJ/mol and [220.2 ± 2.0–241.1 ± 4.0] kJ/mol, respectively. The Avrami parameter approached half-unity for both ferrite and austenite recrystallized phases for which results can be interpreted to be chiefly responsible for a general mechanism involving the growth of new grains with appreciable initial volume through a diffusion-controlled process.

The role of TiN inoculant on microstructure and properties in wire arc directed energy deposition of super duplex stainless steels

The challenges in Wire Arc Directed Energy Deposition (Wire-DED) of super duplex stainless steels (SDSS) are the growth of large columnar grains and undesirably high austenite content. This results in a detrimental effect on the material properties. Here we report the additively manufactured SDSS with the addition of TiN inoculant via Wire-DED. And the effectiveness of incorporating TiN inoculant into additively manufactured SDSS was explored. The addition of trace amounts of TiN reduced the content of the austenite phase from 74.0% to 61.5%. Additionally, the introduction of TiN facilitated deoxidation and slag formation, leading to decreased inclusion content and a shift in inclusion type, which acted as nucleation sites for ferrite, promoting grain refinement. This results in weakened anisotropy of tensile properties and enhanced corrosion resistance. The anisotropy of the ultimate tensile strength and yield strength reduced from 9% to 3% and from 5% to 2%, respectively. This study demonstrates the potential of TiN inoculation in fabricating Wire-DEDed SDSS with tailored microstructures and improved performance, making them suitable for a wide range of practical applications.

Interweaved filler network in epoxy resin with reduced interface thermal resistance via in-situ high-temperature “welding” for significantly improved thermal conductivity

For heterogeneous integration in harsh environments, polymeric materials are required to integrate excellent insulating property with significant thermal conductivity. Traditional discrete fillers used in polymeric matrix to create thermal pathways introduce numerous contact interfaces, leading to limited thermal conductivity enhancement efficiency (TCE) and unstable dielectric properties. Here, a distinctive strategy, involving the preparation of an interweaved thermally conductive filler with inherent heat channels through self-templated electrospinning and in-situ high-temperature “interface welding”, is proposed to reduce the interface thermal resistance (ITR). The growth of grains at high temperature facilitates the process of “interface welding”, while self-templated electrospinning establishes intrinsic thermal conduction pathways. Consequently, the epoxy resin fortified with this interweaved filler exhibits an exceptionally TCE of 162.15 % and enhanced in-plane thermal conductivity of 3.75 W m−1 K−1 at ultra-low filler ratio of 7.10 vol%. The combination of high electrical insulation of filler and low filler content results in excellent electrical insulating property (>1017 Ω cm) and stable dielectric properties over a frequency range of 103-106 Hz, enabling the successful implementation of heterogeneous integration in challenging environments. This work has the potential to offer a groundbreaking approach for achieving interconnected functional networks within polymer-based composites.

Microstructure evolution and mechanical properties of Mg94Sn3Al2Zn1 alloy under different extrusion processes

Mg alloys offer potential value in the research and application of structural materials, optimizing superior extrusion processes for this purpose has been a major emphasis. This study examined the impact of five extrusion processes (two conventional forward extrusion and three innovative ES techniques) on the microstructure evolution and mechanical properties of Mg94Sn3Al2Zn1 (wt.%) alloys. Findings show that the ES technique dramatically improved the plasticity of the alloy whereas retaining its high strength. Among all the ES samples, the ES-105 sample exhibited the best tensile properties at room temperature. Mechanical properties differ significantly based on microstructure evolution, with CDRX and DDRX being the primary mechanisms for microstructure evolution in Mg94Sn3Al2Zn1 alloys. Compared to the FE samples, the ES samples are distributed with finer and more homogeneous DRXed grains, and the texture components obviously modify, distinguishing from the basal texture in the FE samples, which exhibit recrystallization texture after extrusion. The as-extruded alloy contains mainly Mg2Sn and a small amount of Mg17Al12 as well as denser and finer second phases in the ES samples. These second phases are crucial in weakening the texture by facilitating the recrystallization process via PSN mechanism, thereby inhibiting the growth of the DRXed grains.

The Effect of Static Recrystallisation of Parent Austenite on the Lath Martensite Intervariant Boundary Network

The current study investigated the effect of static recrystallisation (SRX) of parent austenite microstructure on the lath martensite intervariant boundary network. In general, the misorientation angle distribution of lath martensite exhibited a bimodal distribution in the range of 10–22 deg and 47–60 deg for all thermomechanical conditions, closely matching the misorientations expected from the ideal Kurdjumov-Sachs orientation relationship. Nevertheless, the population of 60 deg misorientation angle initially reduced with the extent of softening up to 50 pct beyond which it progressively increased to a maximum in the fully recrystallised condition. This was closely consistent with the trend noticed for the 60 deg/[110] intervariant boundaries having twist character. This was explained through the distinct variant selection mechanism occurring due to the change in the parent austenite grain characteristics (i.e., size and deformed state) upon static recrystallisation. The recrystallisation initially led to the formation of fine dislocation-free parent austenite grains up to 50 pct softening, promoting a 4-variant (V1V2V3V4) clustering arrangement to decrease the strain related to the martensite transformation. In turn, this promoted the formation of symmetric tilt 60 deg/111¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\left[ {11\\overline{1}} \\right]$$\\end{document} intervariant boundaries, which ultimately reduced the 60 deg/110\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\left[ {110} \\right]$$\\end{document} boundaries. Further softening, accompanied with the growth and/or coalescence of parent austenite grains, altered the variant clustering to a 3-variant arrangement (V1V3V5) and the increase in 60 deg/110\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\left[ {110} \\right]$$\\end{document} twist intervariant boundaries. Indeed, the martensite boundary network was largely controlled by the SRX parent austenite characteristics (i.e., size), which can be controlled to enhance the materials performance for a given application.

Principles of amyloplast replication in the ovule integuments of Arabidopsis thaliana.

Plastids in vascular plants have various differentiated forms, among which amyloplasts are crucial for starch storage and plant productivity. Despite the vast knowledge of the binary-fission mode of chloroplast division, our understanding of the replication of non-photosynthetic plastids, including amyloplasts, remains limited. Recent studies have suggested the involvement of stromules (stroma-filled tubules) in plastid replication when the division apparatus is faulty. However, details of the underlying mechanism(s) and their relevance to normal processes have yet to be elucidated. Here, we developed a live analysis system for studying amyloplast replication using Arabidopsis (Arabidopsis thaliana) ovule integuments. We showed the full sequence of amyloplast development and demonstrated that wild-type amyloplasts adopt three modes of replication, binary fission, multiple fission, and stromule-mediated fission, via multi-way placement of the FtsZ ring. The minE mutant, with severely inhibited chloroplast division, showed marked heterogeneity in amyloplast size, caused by size-dependent but wild-type modes of plastid fission. The dynamic properties of stromules distinguish the wild-type and minE phenotypes. In minE cells, extended stromules from giant amyloplasts acquired stability, allowing FtsZ ring assembly and constriction, as well as the growth of starch grains therein. Despite hyper-stromule formation, amyloplasts did not proliferate in the ftsZ null mutant. These data clarify the differences between amyloplast and chloroplast replication and demonstrate that the structural plasticity of amyloplasts underlies the multiplicity of their replication processes. Furthermore, this study shows that stromules can generate daughter plastids via the assembly of the FtsZ ring.

Effect of Cu content on microstructure and properties of Ti-6Al-4V alloy fabricated by double-wire arc additive manufacturing

To solve the formation of coarse columnar β grains from Ti-6Al-4 V parts fabricated by wire + arc additive manufacturing, this study adds Cu element for in-situ alloying, effectively suppressing the growth of columnar grains and further enhancing properties. The results show that an addition of Cu element suppresses the lateral growth of β grains, eliminating the columnar structure of β grains. Compared with the Ti-6Al-4 V component, the original β grains in the Ti-6Al-4 V-10Cu component exhibit a refinement of 96 %. With an increase of Cu content, the phase structure of α-Ti transitions from lamellar to needle-like and eventually to equiaxed crystal structure. Moreover, as the Cu content rises, the precipitation of Ti2Cu increases, leading to precipitation strengthening and enhancing the microhardness. The average strength of the Ti-6Al-4 V-10Cu, Ti-6Al-4 V-11.7Cu, and Ti-6Al-4 V-15.7Cu walls is increased by 35.5 %, 56.9 %, and 71.6 %, respectively, compared with the Ti-6Al-4 V wall. The ultimate tensile strength is enhanced by 34.9 %, 49.5 %, and −1.4 %, respectively. However, the elongation is reduced by 48.6 %, 63.2 %, and 75.6 %, respectively.

Homoepitaxy of Boron Nitride on Exfoliated Hexagonal Boron Nitride Flakes.

Although large efforts have been made to improve the growth of hexagonal boron nitride (hBN) by heteroepitaxy, the non-native substrates remain a fundamental factor that limits the quality. This problem can be solved by homoepitaxy, which is the growth of hBN on hBN substrates. In this report, we demonstrate the homoepitaxial growth of triangular BN grains on exfoliated hBN flakes by Metal-Organic Vapor Phase Epitaxy and show by atomic force microscopy and photoluminescence that the stacking of these triangular islands can deviate from the AA' stacking of hBN. We show that the stacking order is enforced by the crystallographic direction of the edge of the exfoliated hBN flakes, with armchair edges allowing for centrosymmetric stacking, whereas zigzag edges lead to the growth of noncentrosymmetric BN polytypes. Our results indicate pathways to grow homoepitaxial BN with tunable layer stacking, which is required to induce piezoelectricity or ferroelectricity.

Fostering Charge Carrier Transport and Absorber Growth Properties in CZTSSe Thin Films with an ALD-SnO2 Capping Layer.

The present study demonstrates that precursor passivation is an effective approach for improving the crystallization process and controlling the detrimental defect density in high-efficiency Cu2ZnSn(S,Se)4 (CZTSSe) thin films. It is achieved by applying the atomic layer deposition (ALD) of the tin oxide (ALD-SnO2) capping layer onto the precursor (Cu-Zn-Sn) thin films. The ALD-SnO2 capping layer was observed to facilitate the homogeneous growth of crystalline grains and mitigate defects prior to sulfo-selenization in CZTSSe thin films. Particularly, the CuZn and SnZn defects and deep defects associated with Sn were effectively mitigated due to the reduction of Sn2+ and the increase in Sn4+ levels in the kesterite CZTSSe film after introducing ALD-SnO2 on the precursor films. Subsequently, devices integrating the ALD-SnO2 layer exhibited significantly reduced recombination and efficient charge transport at the heterojunction interface and within the bulk CZTSSe absorber bulk properties. Finally, the CZTSSe device showed improved power conversion efficiency (PCE) from 8.46% to 10.1%. The incorporation of ALD-SnO2 revealed reduced defect sites, grain boundaries, and surface roughness, improving the performance. This study offers a systematic examination of the correlation between the incorporation of the ALD-SnO2 layer and the improved PCE of CZTSSe thin film solar cells (TFSCs), in addition to innovative approaches for improving absorber quality and defect control to advance the performance of kesterite CZTSSe devices.

Control of Fusarium Head Blight of Wheat with Bacillus velezensis E2 and Potential Mechanisms of Action.

Wheat plants are impacted by Fusarium head blight (FHB) infection, which poses a huge threat to wheat growth, development, storage and food safety. In this study, a fungal strain was isolated from diseased wheat plants and identified as Fusarium asiaticum F1, known to be a member of the Fusarium graminearum species complex, agents causally responsible for FHB. In order to control this disease, new alternatives need to be developed for the use of antagonistic bacteria. Bacillus velezensis E2 (B. velezensis E2), isolated from a previous investigation in our laboratory, showed a notable inhibitory effect on F. asiaticum F1 growth and deoxynivalenol (DON) synthesis in grains. The spore germination of F. asiaticum F1 was significantly reduced and the spores showed vesicular structures when treated with B. velezensis E2. Observations using scanning electron microscopy (SEM) showed that the hyphae of F. asiaticum F1 were shrunken and broken when treated with B. velezensis E2. The RNA-seq results of F1 hyphae treated with B. velezensis E2 showed that differentially expressed genes (DEGs), which were involved in multiple metabolic pathways such as toxin synthesis, autophagy process and glycan synthesis, especially the genes associated with DON synthesis, were significantly downregulated. In summary, those results showed that B. velezensis E2 could inhibit F. asiaticum F1 growth and reduce the gene expression of DON synthesis caused by F1. This study provides new insights and antagonistic mechanisms for the biological control of FHB during wheat growth, development and storage.

Performance Evaluation of Different Finger Millet (Eleusine coracana L. Gaertn.) Cultivars for Growth, Productivity and Nutrient Quality of Grains Under Hot and Subhumid Region of Odisha

Millets are cultivated world-wide and are more prominent in South Asian and African countries. Among different millets, finger millets hold a significant position in terms of area and productivity. Due to negligence in various cultivation practices and improper selection of genotypes, most farmers fail to achieve optimum yields. In this scenario, the choice of a suitable cultivar is essential. Considering the above, an experiment was conducted at Post Graduate Research Farm of Centurion University of Technology and Management, Odisha, to evaluate suitable cultivars of finger millet. The study consisted of eight treatments comprising of V1: VL Mandua, V2: Hima, V3: Indravathi, V4: Vegavathi, V5: Champavathi, V6: Suvarnamukhi, V7: Bharathi, V8: Sri Chaitanya. The treatments were replicated thrice and the randomized block design was implemented. The results revealed that the highest plant height (158 cm) was observed with the cultivar Bharathi. Indravathi recorded the highest dry matter accumulation at harvest (776 g m-2), leaf area index at 50 DAT (3.56) and number of tillers at 50 DAT (66). However, the highest effective tillers per m2 (2.3) were recorded with the cultivar Sri Chaitanya, and the highest number of grains per ear head and weight per ear head were registered in the Bharathi variety. Further, the highest numbers of fingers per ear head (8.4), 1000 grain weight (2.82g), weight of grains hill-1 (6.72g) and length of finger (7.7cm) were recorded in the variety Indravathi. The cultivar Indravathi recorded the highest grain (2315 kg ha-1), stover (5372 kg ha-1) and biological yield (7687 kg ha-1) and Sri Chaitanya followed it. The study concludes that Indravathi and Sri Chaitanya can be considered short-duration and Hima as long duration cultivar for obtaining higher yield during Kharif season (July to September) under the hot and subhumid regions of Odisha.

Strengthening and Toughening of ZG25SiMn2CrB Steel without Tempering Brittleness via Electropulsing Treatment.

High-strength low-alloy steels are widely used, but their traditional heat-treatment process is complex, energy-intensive, and makes it difficult to fully exploit the material's potential. In this paper, the electropulsing processing technology was applied to the quenching and tempering process of ZG25SiMn2CrB steel. Through microstructural characterization and mechanical property testing, the influence of electropulsing on the solid-state phase transition process of annealing steel was systematically studied. The heating process of the specimen with the annealing state (initial state) is the diffusion-type transition. As the discharge time increased, the microstructure gradually transformed from ferrite/pearlitic to slate martensite. Optimal mechanical properties and fine microstructure were achieved after quenching at 500 ms. The steel subjected to rapid tempering with 160 ms electropulsing exhibited good, comprehensive mechanical properties (tensile strength 1609 MPa, yield strength 1401.27 MPa, elongation 11.63%, and hardness 48.68 HRC). These favorable mechanical properties are attributed to the coupled impact of thermal and non-thermal effects induced by high-density pulse current. Specifically, the thermal effect provides the thermodynamic conditions for phase transformation, while the non-thermal effect reduces the nucleation barrier of austenite, which increases the nucleation rate during instantaneous heating, and the following rapid cooling suppresses the growth of austenite grains. Additionally, the fine microstructure prevents the occurrence of temper brittleness.

A novel strategy to enhance the interfacial bonding quality of CoCrFeMnNi high-entropy alloy joints produced by vacuum hot-compression bonding

The strain history of strain rate transient changes was introduced into the vacuum hot-compression bonding (VHCB) process of CoCrFeMnNi high-entropy alloy, which rapidly improved the interfacial bonding quality of the joint. The results of interfacial microstructure characterization indicated that the high-density dislocations generated in the interfacial region during the initial high strain rate stage not only promoted the nucleation of the interfacial recrystallized grains but also induced the transformation of the sub-boundaries and the interfacial grain boundaries (IGBs) to the high mobility twin boundaries (TBs). The accelerated discontinuous dynamic recrystallization process, the growth of TB-type continuous dynamic recrystallization grains, and the interfacial TB migration during the transient VHCB dramatically enhance the IGB migration level of the joints. This study provides an effective strategy for the interfacial regulation of high-quality VHCB joints.

Large-Scale Multi-Phase-Field Simulation of 2D Subgrain Growth

The characteristics of subgrains in a deformed state after the high-temperature deformation of aluminum alloys control the subsequent recrystallization process and corresponding mechanical properties. In this study, systematic 2D phase-field simulations have been conducted to determine the role of deformed state parameters such as subgrain size and disorientation distributions on subgrain growth in an individual grain representing a single crystallographic orientation. The initial subgrain size and disorientation distributions have been varied by ±50%. To have a statistically relevant number of subgrains, large-scale simulations have been conducted using an in-house-developed phase-field code that takes advantage of distributed computing. The results of these simulations indicate that the growth of subgrains reaches a self-similar regime regardless of the initial subgrain structure. A narrower initial subgrain size distribution leads to faster growth rates, but it is the initial disorientation distribution that has a larger impact on the growth of subgrains. The results are discussed in terms of the evolution of the average diameter of subgrains and the average disorientation in the microstructure.

Modulating secondary growth of perovskite grains through residual solvent evaporation

Over the past decade, perovskite solar cells (PSCs) have attracted enormous attention due to their high performance. One key to fabricating high-quality perovskite films lies in controlling the volatilization rate of residual solvents during the annealing process. This study systematically investigates how different protective substrates affect the volatilization rate of residual solvent in perovskite films. By adjusting the direction and rate of evaporation, the supersaturation time of the solution was precisely controlled, leading to effective recrystallization of the grains. Concurrently, the annealing time was optimized to enhance film quality further. This optimization aimed to increase crystallinity, reduce defects, and thereby minimize non-radiative recombination centers. Implementing these methodologies, particularly the use of filter paper as a protective substrate during a 2-minute annealing process, significantly improved the fill factor (FF) and open-circuit voltage (VOC) of the PSCs. This led to a remarkable 5.26% improvement in power conversion efficiency (PCE) compared to control devices. The strategies employed in this work demonstrate significant potential in improving PSC film quality. This approach not only advances our understanding of film formation dynamics but also provides a practical guideline for future PSC fabrication.

Obtaining extremely low coercivity of high Bs FeCoBSiCPCu nanocrystalline alloys through modulation of magnetic anisotropy

Longitudinal magnetic field annealing is utilized for modifying the magnetic anisotropy and enhancing the magnetic softness of Fe75Co8(B10Si3C3P1)1-x/17Cux (x = 0.5, 0.75, 1, 1.25) nanocrystalline alloys. All of the magnetic field-annealed nanocrystalline alloys with Cu content more than 0.5 at.% exhibit significantly improved soft-magnetic properties, including high saturation magnetic flux density up to 1.87 T, effective permeability of 13,000–16,000 under the condition of 1 A/m and 1 kHz, coercivity as low as 1.6 A/m, and core loss of 0.11–0.45 W/kg under the condition of 1.0 T and 50 Hz. The application of a magnetic field promotes the nucleation and inhibits the growth of grains, leading to an increase in the number density of nanocrystals and the crystalline volume fraction, and a reduction in the grain size. The magnetic field annealing reduces the effective magneto-crystalline anisotropy energy to 2–4 J/m3, and induces longitudinal magnetic anisotropy with anisotropy energy density of 400–900 J/m3 which shows dependence on the crystalline volume fraction. The field-induced magnetic anisotropy dominates over the random local magnetic anisotropies, and results in the formation of regular magnetic domains aligned longitudinally, pinning-free domain wall displacement, and thus enhanced soft-magnetic properties.