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In this paper, the as-quenched Mn 55 Fe 15 Si 20 B 7 EM 3 (EM = Zr, Nb, V) amorphous ribbons were produced by the melt spinning technique. The crystallization behavior, nanoprecipitate phase evolution, and magnetic properties of the Mn-Fe-Si-B-EM (EM = Zr, Nb, V) amorphous alloys were investigated by X-ray diffraction (XRD), differential scanning calorimeter (DSC), and the quantum design dynacool-9 physical property measurement system (PPMS). The Mn 55 Fe 15 Si 20 B 7 EM 3 (EM = Zr, Nb, V) amorphous alloys show two-stage crystallization behavior. In the first stage, the primary crystallization results in the formation of α-Mn + Mn 6 Si/Mn 3 Si precipitates, while in the second stage, the secondary crystallization leads to the formation of the Mn 2 B phase. The Mn 55 Fe 15 Si 20 B 7 Zr 3 (FZ) amorphous sample shows a most significant two-stage phase transformation, which the onset temperature of the primary and that of the secondary crystallization are 625.7 °C and 681.2 °C, respectively. The FZ amorphous sample undergoes a magnetic phase transformation from the spin glass (SG) state to a paramagnetic (PM) state at approximately 28 K. As the temperature increases, the magnetic phase transition can be expressed as: SG → PM. The annealed FZ nanocrystalline sample with α-Mn + Mn 6 Si nano phases enters the ferromagnetic (FM) state at 27∼70 K after undergoing spin glass transformation, and the magnetic phase transition is: SG → FM → PM. The annealed Mn 55 Fe 15 Si 20 B 7 V 3 nanocrystalline sample containing nano α-Mn and Mn 3 Si phases shows two Curie transitions at 57 K and 130 K, respectively. The magnetic phase transition behavior can be expressed as: SG → FMΙ → FMΙΙ → PM. [ABSTRACT FROM AUTHOR]

The glass formation, crystallization behavior, phase precipitation, and magnetic properties for a series of melt-spun Mn 93−x Si x B 7 (x = 15, 20, 25, 30) amorphous ribbons were investigated. For x = 15 and 20 amorphous alloys, the crystallization shows one-stage behavior but different precipitated phases. For x = 25 amorphous alloy, a two-stage crystallization behavior occurs, in which the first and second crystallized peaks precipitate the Mn 5 Si 3 and Mn 2 B, respectively. The broad maximum peak emerges at the temperature-dependent magnetization M (T) curves, indicating the amorphous alloys' spin glass (SG) behavior. Furthermore, the nanocrystalline and amorphous composite structure (NACS) consisting of the single nanocrystalline Mn 5 Si 3 and amorphous phase can be achieved for the amorphous Mn 93−x Si x B 7 alloy with x = 25 by controlling the annealing temperature and duration. The magnetic transitions of the NACS sample significantly differ from the counterpart of its amorphous state. The amorphous alloy undergoes the magnetic phase transition from SG into a paramagnetic state at about 20 K. In comparison, the annealed NACS sample first transforms the SG into a ferromagnetic state at about 15 K and then into a paramagnetic state around 300 K. The difference could attribute to the coupling effect between the nanocrystalline Mn 5 Si 3 with the amorphous phase. • A novel ternary manganese-based Mn-Si-B amorphous ribbons were produced by melt spinning technique. • The Mn 93−x Si x B 7 (x = 15, 20) alloys show one-stage crystallization behavior while x = 25 alloy presents two-stage. • Si composition have noticeable influence on phase formation for Mn-Si-B amorphous alloys during the crystallized annealing. • The Mn 5 Si 3 nanocrystalline and amorphous composite structure (NACS) can be achieved after annealing for x = 25 alloy. • The annealed NACS sample shows great different in magnetic phase transition from the counterpart of amorphous state. [ABSTRACT FROM AUTHOR]

• The Fe-Si-B-Cu-Nb amorphous ribbons with systematical phosphorus substitution were produced by melt spinning method. • The suitable addition of 1 at.% of P in silicon-rich Fe-Si-B-Cu-Nb can improve the glass forming ability of the alloys. • Expanding the heat treatment temperature range to obtain low coercivity, leading to higher permeability at low frequency. • The magnetic permeability in high P-containing Fe-Si-B-Cu-Nb nanocrystalline alloys becomes insensitive to frequencies at high frequencies region. Fe-Si-B-Cu-Nb nanocrystalline alloys exhibit excellent soft magnetic properties and have been increasingly applied in high frequencies ranging from several kHz to several hundred kHz, but the magnetic permeability needs further to design to meet the magnetic components under different frequencies. In the present work, the influences of phosphorus substitution on amorphous forming, crystallization behavior and soft magnetic properties of silicon-rich Fe-Si-B-Cu-Nb alloys were systematically investigated. It was found that the suitable addition of 1 at.% of P in Fe-Si-B-Cu-Nb alloy can significantly improve the amorphous forming ability, reduce the coercivity (H c) of the annealed alloys and elevate the effective magnetic permeability (μ e) at frequencies ranging from 1 to 30 kHz in spite of having fractional detriment to the alloy's thermal stability but still remaining a relatively broad annealing temperature region. Besides, the μ e in high P-containing alloys becomes insensitive to frequencies at high frequencies region, which can attain frequencies-dependent constant magnetic permeability induced by composition design. [ABSTRACT FROM AUTHOR]

In the present work, a series of novel manganese-based Mn-Si-B glassy alloy ribbons were produced by melt-spinning technique. The effects of B/Si ratios on glass formation, thermal stability and magnetic properties for Mn 78 Si 22-x B x (x = 5, 6, 7, 8, 9, 10) alloys have been studied by X-ray diffraction (XRD), differential scanning calorimeter (DSC) and physical property measurement system (PPMS). With increasing B/Si ratios, the glass forming ability of the alloys improves but the thermal stability first increases and then decreases. The Mn 78 Si 22-x B x alloy with x = 8 exhibits the highest onset temperature of crystallization of 898.5 K, which the onset activation energy of crystallization is E x (K) = 337 ± 14 kJ⋅mol−1 and E x (O) = 334 ± 13 kJ⋅mol−1 by using the Kissinger and Ozawa models, respectively, showing a rather high thermal stability. Furthermore, thermal-magnetization M(T) curves demonstrate that the Mn 78 Si 22-x B x glassy alloys exhibit a characteristic spin glass behavior below 22 K. [ABSTRACT FROM AUTHOR]

We used the single copper roll melt-spinning technique to prepare complete Fe57Co5Ni20Si4B14 amorphous alloys. The effect of magnetic field heat treatment on the crystallization behavior, DC-bias characteristic and constant magnetic permeability properties of Fe57Co5Ni20Si4B14 amorphous alloys magnetic cores was investigated. After magnetic field heat treatment, the amorphous alloy cores and slightly nanocrystalline show lower coercivity and good effective magnetic permeability is about 2690, from 1 to 1000 kHz. After magnetic field heat treatment at 623 K, the magnetic core has the best performance that shown 98.8% DC-bias performance in the frequency range from 1 to 1000 kHz. [ABSTRACT FROM AUTHOR]

• To fabricate Si-rich Fe-Cu-Nb-Si-B-(P, Mo) amorphous alloy ribbon by the copper roller melting spinning technique; • The addition of P makes an improvement in effective magnetic permeability (µ e) at low frequency range (1 kHz–20 kHz); • The addition of Mo makes the µ e reduction slow with increasing frequency, successfully achieving a higher µ e at high frequency range (beyond 30 kHz). Fe-Si-B-Cu-Nb nanocrystalline alloys have been commercially applied at higher frequencies. However, few research works are focused on improving high-frequency magnetic properties for these alloys. In this paper, we reported crystallization behavior, soft magnetic properties and permeability spectra for silicon-rich Fe 72.5 Si 16 B 7 Cu 1 Nb 3.5 -xMx (where × = 1.5 and M = Nb, P, Mo, V) nanocrystalline alloys prepared by crystallization from amorphous precursors. Through the copper roller melting spinning technique, we can attain complete amorphous alloy ribbons when M is 1.5 at.% Nb, P or Mo. After annealing at appropriate temperatures, by comparison with the alloy of M = 1.5 at.% Nb, the alloy with addition of 1.5 at.% P shows a lower coercivity (H c = 0.8 ~ 1.5 A/m), and a higher effective permeability (µ e) at 1 kHz–20 kHz (µ e = 116,600 at 1 kHz) while the µ e gets much lower at 30 kHz–200 kHz; the alloy with addition of 1.5 at.% Mo exhibits a larger H c (H c = 2.9 ~ 3.4 A/m), and a lower µ e at 1 kHz − 20 kHz but then the µ e becomes higher at 30 kHz–200 kHz (µ e = 31,000 at 100 kHz). [ABSTRACT FROM AUTHOR]

Ni x Cu 0.2 Zn y Fe 1.98 O 4 (x = 0.16, 0.26, 0.35, 0.43, 0.50; y = 0.8− x) ferrites were prepared via solid-state reaction. The influence of Ni2+ concentration on ferrites composition, microstructure, magnetic properties and DC-bias superposition characteristics was studied by XRD, SEM, XPS, and VSM. Then, the effect of magnetic properties on the DC-bias superposition characteristics was analyzed. The results showed that the ferrites sintered at 900 °C for 3 h were all in pure spinel phase with an average grain size of 7.5 μm and a relative density of about 5.15 g cm−3. With the increase in Ni2+ concentration, the saturation magnetization (M s) and coercivity (H c) of ferrites increased, but the magnetocrystalline anisotropy constant (K 1) first increased and then decreased. And the M s , H c , and K 1 of the specimen with x = 0.43 were 63.62 emu·g−1, 27.36 Oe, and 1813.17 Oe·emu·g−1, respectively. In particular, the specimen of x = 0.50 achieved the best DC superposition characteristics, where the H 70% was about 220 A m−1. The incremental permeability of the specimens decreased rapidly at a bias magnetic field <400 A m−1. The variation mainly originated from the domain wall displacement, and the rate of decrease was influenced by both M s and K 1. At a bias magnetic field ≥400 A m−1, the incremental permeability of the specimens decreased slowly, mainly because the number of domain walls decreased until disappearing, and the specimens tended to become a single domain structure. And the rate of decrease of incremental permeability was mainly affected by K 1. [ABSTRACT FROM AUTHOR]

Improve the Finemet alloy properties by adding Ni elements, and through change the Ni content to control the composition of the alloy system, the alloy has resistance to DC bias characteristics and excellent soft magnetic properties. In the Fe 79.5-X Si 6 B 12 Cu 1 Nb 1.5 Ni X (X = 0, 1, 3, 5, 7, 10) alloy, increasing the content of Ni improves the amorphous forming ability of the alloy, and increased thermal stability, the soft magnetic performance has also been improved. with X is about 10 at.% the nanocrystalline core of alloy ribbon annealed show μ is about 3.4 k, and Hc is about 17.51 A/m. The addition of Ni is beneficial to improve the linearity of the hysteresis loop, when the amount of Ni content increases, the linearity is significantly improved, Ni10at.% alloy shows good DC bias resistance in the magnetic field. And tensile stress has also been improved linearity of the hysteresis loop, make the alloy shows good DC bias resistance in the magnetic field of 0–600 A/m. So it has constant magnetic permeability in this magnetic field, the alloys to be a kind of promising material for current transformer with direct current tolerance. ● When the Ni content is between 0at% and 10at%, increasing the content Ni improves the amorphous forming ability of the alloy. ● Increasing the content Ni improve the hysteresis loop linearity of the alloy. ● Tensile stress are beneficial to improve the DC bias resistance of the alloy. [ABSTRACT FROM AUTHOR]

Due to the rapid growth of precipitated nanoparticles in ultrahigh Fe content nanocrystalline alloys, we propose a new method of low-pressure stress annealing (LPSa) to control crystallization behavior to achieve excellent magnetic properties and mechanical properties of Fe 85.7 Si 0.5 B 9.3 Cu 0.7 P 3.5 C 0.3 nanocrystalline alloy. It demonstrates that LPSa promotes the precipitation of α-Fe phase and suppresses the growth of nanoparticles, which obtains a higher saturation magnetization of 202.1–206.6 emu/g and a lower coercivity of 6.7–8.2 A/m. Besides, the formation of fine and uniform nanocrystalline structure induced by LPSa achieves the lower value and uniform distribution of hardness and Young's modulus, resulting in softening. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Effects of the minor addition of similar ferromagnetic elements (Fe, Co, Ni, and Gd), metal element with strong non-metallic properties (Al), and transition metal elements with large atomic radius (V, Hf, Ti, and Cr) on crystallization behavior, magnetic properties and bending ductility of Fe 85 Si 0·5 B 9 P 4 Cu 0·5 C 0.1 M 0.9 alloys were systematically investigated. The addition of Al, Ni, and Co improves the thermal stability and inhibits the growth of the α-Fe grains. Besides, Gd addition causes a large temperature interval, which suppresses the precipitation of secondary phase. Through the optimum heat treatments, the nanocrystalline alloys exhibit excellent soft magnetic properties, such as higher Ms of 191.7–208.7 emu/g and lower Hc of 6.7–12.1 A/m. Due to the nature of brittleness, the shear morphology induced by elemental microalloying is critical for understanding microscopic mechanism of plastic deformation and achieving high toughness amorphous alloys. We demonstrate that the formation of shear bands are related to the degree of amorphization, shear transformation zones and Poisson's ratio. • We successfully developed a new type of FeSiBCuPC-based amorphous alloy. • Elemental microalloying improves soft magnetic properties and toughness. • The alloys exhibit high Ms of 191.7–208.7 emu/g and low Hc of 6.7–12.1 A/m. • The evolution of shear bands helps elucidate the mechanism of plastic deformation. [ABSTRACT FROM AUTHOR]

Effects of the substitution of Si by P on the amorphous forming ability (AFA), soft magnetic properties, and bending ductility of the Fe 84.2 Si 6-x B 9 P x Cu 0.5 C 0.3 (x = 2.0–4.0) alloys were investigated. It finds that the partial substitution of P for Si promotes the formation of amorphous structure. The AFA of alloys is sensitive to the relevant metalloid elements, and the effect of minor C on the AFA is greater than that of B and P elements. The substitution of Si by P decreases the onset temperature of the second crystallization and promotes the possibility of precipitation of the secondary phase. Besides, an increase in P content effectively inhibits the excessive growth of the α-Fe grains, which contributes to the reduction of grain size and Hc. The amorphous alloys exhibit good bending ductility and high hardness induced by the increase of P content. After optimal heat treatments, the Fe 84.2 Si 6-x B 9 P x Cu 0.5 C 0.3 nanocrystalline alloys exhibit excellent soft magnetic properties, such as higher Ms of 194.6–196.2emu/g and lower Hc of 6.1–6.6 A/m. This work helps us to elucidate the crystallization mechanism induced by the composition and is important for achieving excellent soft magnetic properties, good bending ductility and high hardness. • Substitution of Si by P increases the AFA and thermal stability of alloys. • An increase in P leads to the reduction of grain size and Hc. • Suitable P content is essential for good bending ductility and high hardness. • The ribbons exhibit high Ms of 194.6–196.2 emu/g and low Hc of 6.1–6.6 A/m. [ABSTRACT FROM AUTHOR]