Alloy Ribbons Research Articles

Corroded Fe78Si9B13 amorphous alloy as electrocatalyst for oxygen evolution reaction of water splitting

In this work, different amounts of FeOOH are in situ generated on an amorphous Fe78Si9B13 alloy ribbon by potentiostatic cathodic corrosion treatments for different time, including 0.5 h, 1 h, 2 h and 5 h, which are marked as the R-0.5h, R-1h, R-2h and R-5h, respectively. Afterwards, the corroded samples are investigated as electrocatalysts for the oxygen evolution reaction (OER) of water splitting in 1 M KOH. An appropriate amount of FeOOH not only provides more active sites, but also generates hydroxy1 radicals (OH˙) to greatly improve the efficiency of electronic transmission. However, when the surface of samples is covered by the thick and dense FeOOH layer, the catalytic reaction rate sharply decreases. The R-1h sample shows the best OER catalytic performances, which can achieve an overpotential of 356 mV at a current density of 10 mA cm−2 and the Tafel slope of 45 mV dec−1.

Influence of the Glassy Fraction Surface of a ZrCoAlAg Ribbon Alloy on the Bioactive Response to Simulated Body Fluid and Its Effect on Cell Viability

To purpose of this work is to determine the biocompatibility of the Zr58Co21Al9Ag12 alloy; vitreous ribbons of the Zr58Co21Al9Ag12 alloy were obtained by a chill block melt spinner. They were characterized by X-ray diffraction and transmission electron microscopy. Chemical homogeneity was examined by scanning electron microscopy. Similarly, thermal analysis was performed using differential scanning calorimetry. The nanoindentation test was performed with a Berkovich nanoindenter. Subsequently, the bioactivity was evaluated by chemical immersion in simulated body fluid. After immersion, it was characterized by XRD. A cell adhesion test was performed using mesenchymal stem cells from human dental pulp. Cell viability and proliferation were evaluated with a CCK-8 assay using human lymphocytes. The ribbons have crystalline phases close to 20%. The thermal parameters, Young’s modulus, and hardness were obtained. After the immersion test, Ca and P were identified. Ion release does not exceed critical levels for human cells. The alloy has a higher concentration of adhered cells compared to Ti6Al4V. The alloy remains bio-inert with respect to apatite formation; however, it exhibits excellent cell viability, proliferation, and adhesion behavior.

Enhanced degradation performance of Fe75B12.5Si12.5 amorphous alloys on azo dye.

The Fe75B12.5Si12.5 and Fe75B12.5C12.5 amorphous alloy ribbons were prepared by the melt spinning method. The decolorization performances of these ribbons were investigated in details. It is found that the Fe75B12.5C12.5 amorphous ribbons and Fe75B12.5Si12.5 annealed ribbons only adsorbed the azo dye molecules, with no chemical degradation process. However, the Fe75B12.5Si12.5 amorphous ribbons can reduce -N = N- to -NH2 because of their high reactivity and the local galvanic effect that occurred during the reaction to accelerate electron transfer. The reaction rate constant kobs is 0.0872min-1, 0.0474min-1, and 0.0064min-1 for Fe75B12.5Si12.5 amorphous ribbons, Fe75B12.5C12.5 amorphous ribbons, and Fe75B12.5Si12.5 annealed ribbons in the same condition, respectively. Fe75B12.5Si12.5 amorphous ribbons can effectively degrade Acid Orange II (AO II) azo dyes and achieve decolorization by breaking azo bonds in the dye in a short time, indicating the prominent capacity of Fe75B12.5Si12.5 ribbons on the degradation of AO II. Furthermore, the influence of chemical factors such as ribbons thickness, reaction temperature, initial pH, and AO II concentration of the solution on the reaction rate constant kobs of Fe75B12.5Si12.5 amorphous ribbons had also been studied. The kobs can reach 0.177min-1 under optimal conditions. In addition, all the degradation processes in this work were fitted well with the pseudo-first-order kinetic model. The results are guidance for the practical applications, and they have important implications in developing Fe-based amorphous alloys for functional application materials in the field of wastewater treatment.

Electrochemical Performance and Hydrogen Storage of Ni–Pd–P–B Glassy Alloy

The search for hydrogen storage materials is a challenging task. In this work, we tried to test metallic glass-based pseudocapacitive material for electrochemical hydrogen storage potential. An alloy ingot with an atomic composition of Ni60Pd20P16B4 was prepared via arc melting of extremely pure elements in an Ar environment. A ribbon sample with a width of 2 mm and a thickness of 20 mm was produced via melt spinning of the prepared ingot. Electrochemical dealloying of the ribbon sample was conducted in 1 M H2SO4 to prepare a nanoporous glassy alloy. The Brunauer-Emmett-Teller (BET) and Langmuir methods were implemented to obtain the total surface area of the nanoporous glassy alloy ribbon. The obtained values were 6.486 m2/g and 15.082 m2/g, respectively. The Dubinin-Astakhov (DA) method was used to calculate pore radius and pore volume; those values were 1.07 nm and 0.09 cm3/g, respectively. Cyclic voltammetry of the dealloyed samples revealed the pseudocapacitive nature of this alloy. Impedance of the dealloying sample was measured at different frequencies through use of electrochemical impedance spectroscopy (EIS). A Cole-Cole plot established a semicircle with a radius of ~6 Ω at higher frequency, indicating low interfacial charge-transfer resistance, and an almost vertical Warburg slope at lower frequency, indicating fast diffusion of ions to the electrode surface. Charge-discharge experiments were performed at different constant currents (75, 100, 125, 150, and 200 mA/g) under a cutoff potential of 2.25 V vs. Ag/AgCl electrode in a 1 M KOH solution. The calculated maximum storage capacity was 950 mAh/g. High-rate dischargeability (HRD) and capacity retention (Sn) for the dealloyed glassy alloy ribbon sample were evaluated. The calculated capacity retention rate at the 40th cycle was 97%, which reveals high stability.

Electrochemical hydrogen storage, mechanical and thermal behaviors of novel Mg-based alloy

In this study, Mg65Ni25Y5B5 metallic glass synthesized by using the melt-spinning technique was examined in terms of its electrochemical hydrogen-storage characteristics and mechanical and thermal behaviors. The X-ray diffraction and scanning electron microscopy results indicated that the alloy ribbon has a fully amorphous structure. The thermal behavior of the alloy ribbon was determined using flash differential scanning calorimetry (DSC). According to flash DSC results, the amorphous alloy ribbon exhibited a distinct glass transition temperature (T g) and a wide supercooled liquid region (ΔT x = T x − T g) before crystallization. Accordingly, T g and ΔT x are 195 and 63°C, respectively. The mechanical behavior of the magnesium (Mg)-based alloy at room temperature was determined by means of a Vickers microhardness (HV) tester. The microhardness value of the alloy ribbon was measured as 336.8 HV. The discharge capacity of the Mg65Ni25Y5B5 alloy reached 313 mAh/g. The cycle stability revealed that the alloy ribbon protected at least 76.7% of its initial discharge capacity at the 12th charge–discharge cycle.

Relation between quenching wheel speed and microstructure, thermal stability and corrosion resistance of quinary Al-Ni-Y-Co-Si high entropy metallic glass ribbons prepared by melt spinning

To probe the relation between the wheel speed of a single copper roller and the microstructure and performance of high-entropy metallic glasses, in the current study, the microstructure, thermal stability and anti-corrosion properties of quinary Al-Ni-Y-Co-Si high-entropy metallic glass ribbons rapidly solidified by the melt-spinning method with various quenching wheel speeds were investigated by electrochemical impedance spectroscopy, potentiodynamic polarization measurements, thermal analysis and microstructural characterization. The experimental results show that all investigated alloy ribbons present an amorphous nature, but the wheel speed has little influence on the thermal stability of the measured specimens. With increasing wheel speed, the Vickers microhardness of alloy ribbons in the as-received state has a decreasing trend. After annealing at 773 K for 5 min, the XRD patterns of the heat-treated sample exhibit diffraction peaks of the α-Al, Al3Y, Ni74Si26, YCo3 and NiY intermetallic phases. From the electrochemical test, the alloy ribbons fabricated with a wheel speed of 2000 rpm exhibit both the lowest passive current density (3.24 × 10−6 A/cm2) and self-corrosion current density (0.84 × 10−6 A/cm2), indicating the lowest actual corrosion rate and the best corrosion resistance in 3.5 wt.% NaCl solution among the five kinds of alloy ribbons.

Annealing and electrochemically activated amorphous ribbons: Surface nanocrystallization and oxidation effects enhanced for oxygen evolution performance

Annealing and cyclic voltammetry (CV) are essential for the activation of amorphous alloy ribbons. Various amorphous alloy ribbons have been activated in the fields of environmental catalysts using either annealing or CV. However, the combination of the two methods for improving the oxygen evolution reaction (OER) performance has rarely been reported. This combination is expected to significantly improve the OER performance of amorphous ribbons. Here, we developed an “annealing +CV-activation” integrated strategy to treat a free-standing NiFeBSiP ribbon, which as an efficient and stable oxygen-evolving electrode. The “annealing +CV-activation” strategy induces the nanocrystallization and oxidation effects on the surface of the NiFeBSiP ribbon. The effects significantly increase the electron transfer ability, the Ni/Fe/P oxidation state and the surface area of the NiFeBSiP ribbon, which consequently leads to enhancing the OER performance. As a result, the treated ribbon exhibits a low overpotential of 269 mV at 10 mA cm−2 and a small Tafel slope of 40.5 mV dec−1, which are much better than the OER performance of the as-spun ribbon. The enhanced OER performance of the NiFeBSiP ribbon demonstrates the significant and promising effect of the “annealing +CV-activation” integrated strategy for designing high-efficiency amorphous alloy ribbons electrocatalysts.

Enhancement of magnetic properties of Sm-Co nano composite ribbons by heavy lanthanide doping

Sm-Co magnets becoming more and more interesting among research community since 1950′s due to its essential role in space and transport industry to be used in some precious instruments such as, sensors, actuators, motors, and gyroscope. The combination of Rare-earth (RE) and Transition metal (TM) is an ideal combination to make a high-performance magnet, as the RE provides the high magneto crystalline anisotropy (HA) and the TM provides the high magnetization (Ms) and high Curie temperature (Tc). SmCo5 compound possesses Tc as high as ∼ 700 °C. Previous studies have reported that HRE (Gd, Dy, Er and Ho) could be used as a temperature compensation material as unpaired 4f electrons in shell gives rise to maximum magnetic moment. In this study, effect of lanthanides (HREs - Gd and/ Dy) on microstructure and magnetic properties of Sm-Co-based rapidly solidified alloy ribbons have been reported. Phase analyses confirmed the presence of 1:5H phase which was prevalent along with a fraction of 2:17R phase in all the alloy ribbons. Hc value was increased from 10.9 to 13.3 kOe (1.09 to 13.3 T) and Br value was increased from 12.5 to 16.2 kG (1.25 to 1.62 T) with Dysprosium addition.

Effect of beryllium on the morphology of initial ingots and the structural phase state of fast-quenched STEMET 1108 brazing alloy ribbons

The STEMET 1108 grade (copper – tin – indium – nickel) of filler metal is currently used to braze bronze to tungsten plated with pure copper in divertors of the International Thermonuclear Experimental Reactor (or, ITER). Such filler metals are obtained as a result of rapid solidification of melt on a rapidly spinning copper wheel (melt spinning). When ingots are cast from which brazing ribbons are further produced, pores occur in them, through which indium evaporates. All this may affect the quality of the final product. The authors propose to alloy ingots with beryllium to stop the pore formation. This paper looks at the effect of beryllium on the quality of filler metal ingots and ribbons. The paper describes the results of a study that looked at the structural phase state of filler metals using electron microscopy and X-ray diffraction techniques, as well as a synchrotron radiation source. Both ingots and ribbons were found to have the same phase composition that consists of copper-based FCCsolid solutions and contains phosphide Cu3P. Beryllium containing ribbons are thinner than beryllium-free ribbons. In both cases, a dendritic structure is formed across the entire ribbon thickness. It is demonstrated that beryllium alloying in the range of 0.05 to 0.1 wt. % helps to significantly reduce the porosity of the initial ingots without compromising their structural phase state. In addition, it helps prevent the evaporation of indium. Hence, the difference in the structural phase state between beryllium alloyed and non-alloyed ribbons is insignificant and only concerns their dendritic structure, while there is no noticeable difference in their phase composition.

Investigation of exchange bias and magnetoresistance in the Si substituted Ni-Mn-In ribbon alloys

We have studied the effect of Si substituted Ni-Mn-In alloy on the exchange bias (EB) and Magnetoresistance (MR) and found that the Curie temperature of martensite phase increases with Si substitution and vanishes for × = 3 ribbon alloy. The splitting of ZFC and FC curve at low temperature confirms the exchange bias phenomenon in the ribbons. The step like behavior in the isothermal ZFC curve also confirms the exchange bias behavior. The coercive field initially increases with temperature and reaches a maximum value at 40 K, and then decreases with the increase of temperature confirms the vanishing of EB in the ribbons with the temperature. The large exchange bias field of 687 Oe is found in × = 1 ribbon at 5 K.. A large negative magnetoresistance of 22.4% is found at 260 K for × = 1 ribbon. The change in magneto resistance can be attributed to the super zone boundary nearby Fermi surface.

Electric explosion of amorphous iron alloy ribbons in water and in ethylene glycol

Electric explosions of amorphous ribbons (Fe45Co45Zr7B3 HITPERM, Fe73.5Si15.5B7Nb3Cu1 FINEMET, and bulk amorphous Fe71.6Mn0.6Si3.4C12.3B12.2) were studied in water and for the bulk amorphous alloy in ethylene glycol, in order to study whether the amorphous state can be preserved in the process. Formed products were collected and analyzed by Scanning Electron Microscopy, X-ray diffraction, Mössbauer spectroscopy, and High-Resolution Transmission Electron Microscopy. Chemical reactions have taken place in large extent between melted and evaporated components of ribbons and the decomposed cooling media. The oxidation reactions removed quickly the glass-forming elements (Zr, B, Si) from the metallic particles. Oxides were formed both on surface of globules and in separate phases from evaporated components. The amorphous state was partly retained in FINEMET, and to a greater extent in bulk amorphous alloy. Chemical interactions were more limited in ethylene glycol and carbon atoms formed from the decomposed coolant contributed to stabilization of amorphous phase.Graphical abstract

Magnetic properties and magnetocaloric effect of GdTbHoEr-based high-entropy alloy ribbons

Magnetic properties and magnetocaloric effect of GdTbHoEr-based high-entropy alloy ribbons

Nanoporous Copper Ribbons Prepared By Chemical Dealloying of a Melt-Spun Zn-Cu Alloy

Dealloying process is a powerful and versatile method to fabricate three-dimensional nanoporous (np) materials for applications in electrochemical synthesis, sensors, and catalysis. In the last years, several morphologies of np-copper and their dealloying mechanisms have been reported in alkaline and acidic media.[1-4] For instance, the nature of anions such as chloride and phosphate strongly influence the ligament size of np-Cu. The effects of several experimental parameters to control the structural and chemical properties of np-Cu materials via dealloying are not fully understood to date.In our work, Zn80Cu20 alloy ribbons prepared by melt-spinning were dealloyed by free corrosion in 0.1 M HCl and 1.3 M NaOH solutions. Both the surface and cross-section of the obtained np-Cu ribbons were comprehensively characterized by SEM, EDX, STEM, XRD, and XPS. Our results show a clear relation between dealloying conditions (pH, kind of electrolyte and reaction time) and structural parameters (ligament size and chemical composition) for np-Cu ribbons. The ligament size is strongly coupled with the residual Zn content prepared by dealloying in acidic environment. In contrast, the ligaments produced in alkaline media are much smaller, whereas the residual Zn content can be tuned in a broad range without changes in ligament size. For the first time, we point out the distribution of residual Zn within single ligaments of np-Cu. We suggest that the Cu surface atoms diffuse and capture the Zn atoms which are located in the near-subsurface during dealloying. Therefore, the Zn-rich regions seem to be relicts of the master alloy. We have also evaluated the time-resolved evolution of porosity within the ribbons via cross-section analysis. Despite the relatively thick melt-spun ribbons (35 ± 3 μm), kinetics of a bicontinuous ligament-pore structure are controlled by the interfacial process instead of the diffusion of corrosive electrolyte solution in and out of the porous layers, referred to as long-range mass transport. Surface diffusivities of Cu at 25 °C were determined to be 1.4 × 10−18 and 9.4 × 10−21 m2 s−1 in 0.1 M HCl and 1.3 M NaOH, respectively. Therefore, the high Cu surface diffusion rate in the presence of chloride ions enables an enhanced dealloying front propagation into the ribbons, and also coarsening of the ligaments to form larger ligament. On the contrary, the slow surface diffusion rate of Cu (hydr)oxide in 1.3 M NaOH solution strongly limits the dealloying process and forms smaller ligaments. Moreover, dealloying temperature strongly influences the surface diffusivity of Cu, leading to a strong relationship between dealloying temperature and the np-Cu structure. The electrochemically active surface area of np-Cu ribbons was determined by double layer capacity method. The catalytic properties of the np-Cu ribbons were then evaluated for organic electro-synthesis of cyclic carbonates from CO2 and epoxide. The yield of cyclic carbonate could be improved by using np-Cu ribbons for the activation of CO2.Based on our results, we provide deeper insights to the formation processes of np-Cu ribbons with tunable ligament size and Zn content in various electrolyte environments and its application as electrode material for electro-synthesis of cyclic carbonates formation from CO2 and epoxide.

Experimental investigation of minor Si addition on AlNiYCo multi-principal element alloy: Microstructural characterization, thermal stability and corrosion resistance

High-performance multi-principal element alloys are regarded as novel structural and functional materials and also have attracted extensive research interests in academia as well as industry. In order to develop outstanding anti-corrosion and high-microhardness multi-principal element alloys with superior thermal stability, on the basis of our previous study, the effects of minor Si addition on the microstructure, thermal stability and corrosion resistance of (Al1/3Ni1/3Y1/3)92Co8 multi-principal element alloy were investigated in this current research. It was revealed that all types of as-quenched Si-containing alloy ribbons prepared by melt-spinning method could remain the homogeneous amorphous structures and their crystallization onset temperatures were over 760 K at the heating rate of 20 K/min. The average microhardness value of each specimen was more than 498 HV0.1 as well. The average roughness and the root mean square roughness of these studied metallic ribbons exhibited a roughness of 0.20 nm and 0.27 nm or below. When the Si content elevated from 0.5 to 4 at.%, it gave rise to a increase of pitting potential from −0.222 VSCE of the (Al1/3Ni1/3Y1/3)91.5Co8Si0.5 to −0.207 VSCE of the (Al1/3Ni1/3Y1/3)89Co8Si3 and -0.205 VSCE of the (Al1/3Ni1/3Y1/3)88Co20Si4 glassy alloy ribbons, which can be comparable to that of Al86Ni7Y4.5Co1La1.5 metallic glass ribbons by and large. The alloy ribbons with 3 at.% Si exhibited the outstanding anti-corrosion property in 3.5 wt% NaCl solution since it owned the most positive pitting corrosion potential and the widest overpotential region simultaneously compared with the other alloy ribbons. Therefore, it is supposed that adding minor Si element into (Al1/3Ni1/3Y1/3)92Co8 alloy can promote the ability for resisting pitting corrosion. This research work not only further verifies the available formation of amorphous state by minor Si addition, but also sheds light on the role of Si on thermal stability and anti-corrosion performance of AlNiYCo multi-principal element alloy.

NdFeB esaslı kalıcı manyetik alaşımların manyetik özelliklerine uygulanan ısıl işlemdeki sürenin etkisi

In our current study, NdFeB-based permanent magnet ribbon alloys were produced by using melt spinning method, which is one of the rapid solidification methods and very common in the production of ribbon-shaped, amorphous and/or semi-crystalline alloys. During the production of each NdFeB alloy, 15 wt.% of waste magnet was included in the composition of the alloys. The produced permanent magnet alloys were heat treated for 5 and 10 minutes by using a heat treatment temperature of 710 °C and very high heating and cooling rates of 285 K/s. The effect of the heat treatment time applied at the same temperature on the magnetic properties of the strip alloys was investigated. While the increase in heat treatment time resulted in a remarkable change in magnetic coercivity and maximum energy product properties, there was not much change in the properties such as saturation magnetization and magnetic remenance. As clearly seen, increasing heat treatment time resulted in a continuous decrease in magnetic coercivity from 5030.5 Oe to 2279.4 Oe, maximum energy product first showed a dramatic increase from 62.02 kJ/m3 to 103.73 kJ/m3, and then a dramatic decrease to 38.63 kJ/m3, indicating a decrease in the permanent magnetism of the alloy.

Tailoring the Void Space of a Silicon Anode for High‐Capacity and Low‐Expansion Lithium Storage

Si anodes have been attracting attention because they offer the critical advantages of being derived from abundant sources and exhibiting a high theoretical capacity. However, Si anodes have not been used in practical applications of Li‐ion batteries because of the unavoidable large volume changes that occur during charging and discharging. Herein, rather than considering the active material, the structural design of the Si anode is focused, developing a material whose volume does not expand even after the Li insertion process. The Si anode is fabricated by leaching Al from a rapidly solidified Al–Si alloy ribbon using a single‐roller melt‐spinning process. Si anode ribbons derived from 50Al–50Si alloy consisting of microscale primary Si and nanoscale eutectic Si show a low‐volume expansion when Li is inserted to a capacity of 3000 mAh g−1. Scanning electron microscopy observations show that the formed pores suppress the expansion of the electrode. At a rate of C/10, the electrode alone, without a binder or conductive carbon additive, exhibits good cycling stability; the initial capacity of 2070 mAh g−1 slightly decreases to 1970 mAh g−1 after 10 cycles. These results open a new platform for designing low‐expansion Si anodes for high‐capacity energy‐storage devices.

Structure and magnetic properties of Ni50−xCoxMn50−yAly (x = 5–9, y = 18–19) shape memory alloy ribbons

Alloy ribbons of Ni 50−x Co x Mn 50−y Al y (x = 5, 6, 7, 8 and 9; y = 18 and 19) were fabricated by using melt-spinning method. By varying Co and Al concentrations, the formation of crystalline phases, structural transformations and magnetic phase transitions can be tuned as desired. With high Al and Co concentrations, only a ferromagnetic-paramagnetic (FM-PM) transition of the austenitic phase occurs in the range of 350–450 K. While there is an additional weak ferromagnetic- ferromagnetic (WFM-FM) transition corresponding to the martensitic-austenitic (M-A) structural transformation for the ribbons with low Al and Co concentrations. The M-A transformation temperature of the alloy ribbons can be obtained in the range of 150–360 K. An anomalous change in structure and magnetic properties was observed in the ribbon sample with Co and Al concentrations of 8 and 18 at%, respectively. The external magnetic field has a pronounced effect on the M-A transformation and tends to shift this process towards lower temperatures. • Structure and magnetic properties of Ni 50−x Co x Mn 50−y Al y rapidly solidified alloys. • Influence of Co and Al contents on structural transformation and magnetic transition. • Coexistence of different crystalline phases in Heusler magnetic shape memory alloys. • Tuning structural transformation and magnetic transition of Ni-Co-Mn-Al alloys. • Transformation of metamagnetic phase in Ni-Co-Mn-Al rapidly solidified alloys.

Investigation of Nanoscale Phase Formation in Rapidly Solidified Fe<sub>20</sub>Co<sub>20</sub>Ni<sub>20</sub>Cr<sub>20</sub>B<sub>20−</sub><i><sub>x</sub></i>Si<i><sub>x</sub></i> Alloys

In this study, nanoscale phase formation in rapidly solidified Fe20Co20Ni20Cr20B20−xSix alloys was investigated using atom probe tomography (APT) and transmission electron microscopy (TEM). According to previous X-ray diffraction measurements and scanning electron microscopy with energy-dispersive X-ray spectroscopy results, it was thought that this alloy system was composed of almost a single face-centered cubic (FCC) solid solution phase when the Si content was 5 at.%. However, APT and TEM results at the nanoscale showed that both an FCC solid solution and compound phases formed for all alloy compositions. The rapidly solidified alloy ribbon with a Si content of 5 at.% showed the presence of nanoscale FCC and Cr2B phases. Furthermore, in addition to the nanoscale FCC and Cr2B phases, a nanoscale Cr3Ni5Si2 phase was observed when the Si content exceeded 7.5 at.%.

Compensated ferrimagnetism and compensation temperatures in Mn2-2xCo0.5+xV0.5+xGa Heusler alloys

Melt spun ribbons of Heusler alloys Mn2-2xCo0.5+xV0.5+xGa (x = 0, 0.1, 0.2, 0.25, 0.3, 0.4, 0.5) with 24 valence electrons were synthesized. Curie temperature decreases from 634 to 122 K with decreasing Mn content. Fully compensated ferromagnetic state was achieved for the x = 0.2 and x = 0.4 compositions. The compensation temperature, determined from the Hall resistivity measurements, was found to be ∼130 K for the Mn1.6Co0.7V0.7Ga composition and ∼317.5 K for the Mn1.2Co0.9V0.9Ga composition. Besides, a kink on the magnetization curves of the x = 0–0.4 compounds, observed at T ≈ 70 K, was suggested to be presumably due to a spin-reorientation transition.

Investigation of glass forming ability, crystallization behavior, and soft magnetic properties of Fe–B–P–C–Cu alloy ribbons

The effect of Cu content on GFA, crystallization behavior, and soft magnetic properties in high P Fe84+xB6P6C3Cu1−x (x = 0, 0.2, 0.4, 0.6, and 1.0 at. %) alloy ribbons were systematically investigated to balance the relationship between glass forming ability (GFA), heat treatment window, and soft magnetic properties of high saturation magnetic flux density (Bs) Fe-based nanocrystalline alloys. It was discovered that lowering Cu promotes the formation of an amorphous structure. The GFA of alloys rises from 23 μm for Fe84B6P6C3Cu1 to 29 μm for Fe84.4B6P6C3Cu0.6. Analysis of thermal physical properties shows that when Cu content is between 1.0 at. % and 0.6 at. %, reducing Cu in the alloys does not affect the onset temperature of the first crystallization peak (Tx1), the second one (Tx2), and ΔT (ΔT = Tx2 − Tx1), whereas when Cu content is less than 0.6 at. %, reducing Cu leads to an increase in Tx1 and a decrease in Tx2 and ΔT, which is not conducive to obtaining a wide temperature range of precipitation of a single α-Fe phase. The alloys have a wide range of crystallization annealing temperature (693–753 K) and annealing time (60–6 min) to obtain a low coercivity (Hc) of about 8.0 A/m, high Bs of about 1.80 T, and high effective magnetic permeability (μe) of about 10000 when Cu is between 1.0 at. % and 0.6 at. %. The Bs, Hc, and μe of Fe84.4B6P6C3Cu0.6 alloy annealed at 723 K for 30 min are 1.82 T, 8.1 A/m, and 10820, respectively.