Good Soft Magnetic Properties Research Articles

Microstructure and Soft Magnetic Properties of Fe61Co10Y8Me1B20 (Where Me = W, Zr or Nb) Amorphous Alloys

Microstructure and Soft Magnetic Properties of Fe61Co10Y8Me1B20(Where Me = W, Zr or Nb) Amorphous AlloysThe microstructure and the soft magnetic properties of the multi-component Fe61Co10Y8Me1B20amorphous alloys (where Me = W, Zr or Nb) have been investigated; the samples were in the form of ribbons of 3 mm width and 30 μm thickness. The samples were produced using a single-roller melt-spinning method. The alloy composition was investigated using an X-ray diffractometer. The amorphous nature of the entire volume of all the as-quenched samples was confirmed. From the magnetic measurements performed using the ‘LakeShore’ vibrating sample magnetometer, magnetic parameters such as: coercivity, saturation of the magnetization for the as-quenched samples were derived. All of the investigated alloys displayed good soft magnetic properties, making them perfect materials for magnetic cores. The core losses for different values of magnetic field and operating frequency were also measured. It was shown that the investigated alloys featured lower core losses than commercially-used classical FeSi steel.

Enhancement of glass-forming ability of FeSiBP bulk glassy alloys with good soft-magnetic properties and high corrosion resistance

The effect of Nb micro-addition on the glass-forming ability, magnetic and corrosion properties of (Fe0.76Si0.09B0.1P0.05)100−xNbx (x=0–4) alloy system was investigated. It was found that micro-addition of 1% Nb is effective in increasing the critical diameter for glass formation from 2.5 for the base alloy to 3.5mm for (Fe0.76Si0.09B0.1P0.05)99Nb1 glassy alloy. Moreover, the 1% Nb-containing glassy alloy exhibits excellent soft-magnetic properties, i.e., high saturation magnetization (Is) of 1.45T and low coercive force (Hc) of 1A/m. A significant improvement in corrosion resistance of the glassy alloys with Nb micro-alloying in 1N H2SO4 solution is also observed. The good combination of high glass-forming ability (GFA), excellent soft-magnetic properties and enhanced corrosion resistance indicates the possibility of future development as new engineering and functional materials.

High frequency characteristics of FeCoAlO thin films fabricated with asymmetric target at different Ar gas flow rates

FeCoAlO thin films with good soft magnetic properties were fabricated by using RF magnetron sputtering. In order to obtain good high-frequency performance, the in-plane uniaxial anisotropy was tuned by combining the effects of in situ magnetic field and the gradient of Al–O concentration. The composition gradient was controlled by using an asymmetric target and different Ar gas flow rates changing from 5 sccm to 17.5 sccm. It was found that at the range of Ar gas flow rate from 7.5 sccm to 15 sccm, the films showed an excellent high-frequency performance: the resonance frequency was beyond 3.0 GHz and the real permeability μ′ had a high value of ∼200 at low-frequency side. In particular, the film prepared at the Ar gas flow rate of 15 sccm showed a resonance frequency of 4.0 GHz. Large resonance frequency can be attributed to the high in-plane uniaxial anisotropy field which was induced by stress and the external magnetic field. The high values of permeability and resonance frequency enable the FeCoAlO thin films to be one of the important candidates for microwave applications.

Bulk glassy (Fe0.474Co0.474Nb0.052)100 − x(B0.8Si0.2)x alloys prepared using commercial raw materials

The alloy compositions have been optimized by modifying the B and Si contents in (Fe0.474Co0.474Nb0.052)100−x(B0.8Si0.2)x alloy system with commercial materials. The thermal stability of the supercooled liquid improves with the increased B and Si contents from x=22 to 28. The composition of the alloy with x=26 is close to a eutectic point. By copper mold casting, (Fe0.474Co0.474Nb0.052)100−x(B0.8Si0.2)x bulk glassy alloys with diameters up to 5mm were synthesized for the composition range of x from 22 to 28. In addition to high glass-forming ability (GFA), the (Fe0.474Co0.474Nb0.052)100−x(B0.8Si0.2)x glassy alloys exhibit good soft magnetic properties as well, i.e., rather high saturation magnetization of 0.84–1.07T, low coercive field of 1.8–3.2A/m, high initial permeability of 10100–24100 at 1kHz under a field of 1A/m and Curie temperature of 620–730K.

Enhanced high-frequency electromagnetic properties of FeCoB–SiO2/SiO2 multilayered granular films

A series of FeCoB–SiO2/SiO2 multilayered granular films with various thickness were prepared by alternating co-sputtering FeCoB and SiO2 targets and single-sputtering SiO2 target. As-deposited films were annealed in a magnetic field at different temperature. The high-frequency magnetic and electrical transport properties were investigated. The films annealed above 250°C show good soft magnetic properties and obvious uniaxial magnetic anisotropy. The resistivity (ρ), coercivity (Hce) decrease and complex permeability (μ˜), ferromagnetic resonance frequency (fr) increase with increasing annealing temperature and thickness. The desirable high ρ (∼5.92mΩcm), considerable frequency linewidth (Δf∼4.02GHz) and high μ˜ (μ′=120 at low frequency, μmax″=80) were obtained for the 252nm films annealed at 250°C. The amorphous or nanograin phase and strong exchange coupling effect are responsible for the good high-frequency magnetic performance. The electrical transport properties show the films with high ρ and large μ˜ are near the conductive percolation threshold. Moreover, the Δf, damp coefficient (α) and Gilbert damping parameter (G) were discussed based on phenomenological Landau–Lifshitz–Gilbert equation.

Magnetic properties of Bi2Fe4O9 synthesized by electrospinning

The Bi2Fe4O9 fibrous precursor is successfully synthesized through electrospinning technique, and the single-phase claviform Bi2Fe4O9 is obtained after calcining the precursor. The UV-vis absorption spectrum shows that the absorption range of the as-prepared Bi2Fe4O9 is wide, which indicates that the as-prepared Bi2Fe4O9 could be a photocatalyst with visible-light-driven photocatalytic activity. In addition,the result of magnetic hysteresis loop for Bi2Fe4O9 shows weak ferromagnetism and good soft magnetic properties, which indicate that the as-prepared Bi2Fe4O9 has a good application in soft magnetic material.

FeNiPBNb bulk glassy alloys with good soft-magnetic properties

The effects of Nb content on glass-forming ability (GFA) and soft-magnetic properties of (Fe0.39Ni0.39B0.16P0.06)100−xNbx (x=0, 1, 1.5, 2, 2.5, 3 and 4) glassy alloys were investigated. By adjusting the Nb content, the GFA and soft-magnetic properties are effectively improved. Bulk glassy alloys with diameters up to 2.5mm were synthesized. The FeNi-based glassy alloys exhibit excellent soft-magnetic properties i.e., low coercivity of 1–1.8A/m and high saturation magnetization of 0.66–0.85T. The [(Fe0.5Ni0.5)0.78B0.16P0.06]97.5Nb2.5 glassy alloy also exhibits high effective permeability of 25,700 with excellent frequency stability. In addition to high GFA and good soft-magnetic properties, the alloy shows a constant differential permeability of about 17,700G/Oe and high fracture strength of 3150MPa.

High Frequency Characteristics of Fe65Co35 Alloy Cluster-Assembled Films Prepared by Energetic Cluster Deposition

Size-monodispersed Fe65Co35 alloy clusters whose average sizes ranged from 7 to 12 nm were produced by a plasma-gas-condensation (PGC)-type cluster deposition apparatus. Fe65Co35 alloy cluster-assembled films were further prepared at room temperature by energetic cluster deposition method. Positively charged clusters in a cluster beam were accelerated electrically and deposited onto a negatively biased substrate together with neutral clusters from the same cluster source, leading to the formation of a high-density Fe65Co35 alloy cluster-assembled films with good soft magnetic properties. High frequency magnetic characteristics of these films were studied at room temperature using a high-frequency permeameter (RMF-3000, Ryowa). The real part (micro') of permeability for the Fe65Co35 alloy cluster-assembled films prepared at bias voltage V(a) = -20 kV has a large value of micro' = 135 at f = 1.5 GHz, and imaginary part (micro") of permeability has a maximum (micro" approximately 190) at about 2.5 GHz.

Effect of Ni addition on the glass-forming ability and soft-magnetic properties of FeNiBPNb metallic glasses

The effect of Ni addition on the glass-forming ability (GFA) and soft-magnetic properties of an (Fe1−x Ni x )75.5B14.5P7Nb3 (x=0−0.6) alloy system were investigated. We found that the addition of Ni was effective in allowing the alloy to approach a eutectic point as well as increasing the thermal stability of the supercooled liquid. By increasing the amount of Ni, the supercooled liquid region (ΔT x), the reduced glass transition temperature T rg (T g/T l) and the γ parameter [T x/(T g+T l)] increased from 49 to 75 K, 0.540 to 0.594 and 0.373 to 0.405, respectively. As a result, novel (Fe1−x Ni x )75.5B14.5P7Nb3 bulk metallic glass (BMG) rods with a maximum diameter of 1 mm were synthesized with a composition of x=0.5 and x=0.6 by copper mold casting. These metallic glasses have a moderate saturation magnetization of 0.37–1.20 T with good soft-magnetic properties, i.e. a low coercivity of 1.4–3.3 A/m and a high effective permeability of 13100–20900 at 1 kHz. The simultaneous achievement of a high GFA and good soft-magnetic properties for the FeNi-based alloy system is promising for the future development of BMGs.

Structural and magnetic properties of Fe76P5(Si0.3B0.5C0.2)19 amorphous alloy

Recently, bulk amorphous alloys were produced in the Fe–B–Si–P–C system with high glass forming ability, excellent magnetic properties and the advantage of containing no expensive glass-forming elements, such as Ga, Y, Cr or Nb, having, therefore, a good perspective of commercial applications. In the present work, the Fe76P5(Si0.3B0.5C0.2)19 amorphous alloy prepared by two quenching techniques has been studied. Amorphous ribbons of about 40μm thick were obtained by planar-flow casting together with cylinders having 1 and 2mm diameter produced by copper mold injection casting. All the samples appear fully amorphous after X-ray diffraction analysis. A comprehensive set of thermal data (glass, crystallization, melting and liquidus temperatures) were obtained as well as a description of the melting and solidification processes. Mechanical microhardness tests showed that the samples have a hardness of 9.7±0.3GPa. Good soft-magnetic properties were obtained, including a high magnetization of 1.44T and a low coercivity (4.5A/m for ribbons and 7.5A/m in the case of 1mm rod samples, both in as-cast state). Thermomagnetic studies showed a Curie temperature around 665K and the precipitation of new magnetic phases upon temperatures of 1000K. Furthermore, the frequency dependence of magnetic losses at a fixed peak induction was studied. The results suggest the occurrence of a fine magnetic domain structure in bulk samples. The good soft magnetic properties of the bulk metallic glass obtained by copper mold casting for this particular Fe-based composition suggests possible applications in transformer cores, inductive sensors and other devices.

Effects of C Addition on Glass-Forming in FeCPSiBMoMn Bulk Metallic with Good Soft-Magnetic Properties

The effect of C substitution on the glass forming ability (GFA) and soft magnetic properties of Fe-based bulk metallic glasses (BMG) Fe79.4-xCxSi3.5B5.1P8.9Mo3Mn0.1(x = 4.2, 5.2, and 7.0) alloys have been investigated. It is revealed that fully glassy alloy rods with diameters up to 4 mm can be prepared by conventional copper mold casting method even using the low-cost industrial Fe-P master alloy. Properly substituting of Fe by C gives rise to an enhancement of GFA. Moreover, all the samples exhibit good soft magnetic properties with high saturation magnetization up to 1.16 T and low coercivity of 204 A/m.

Design of soft magnetic CoSiB metallic glass with low Co contents

Based on the topological models of cluster-lines and crystal clusters destabilization, we propose a modified cluster model for designing metallic glasses based on the proposition that distortion of idealized glass-favoring clusters by addition of solute atoms within their solubility limit can enhance glass forming ability. Using the model, two CoSiB metallic glasses of low Co contents (Co63.1B27Si9.9 and Co65B24.4Si10.6) with good mechanical properties are designed. Despite the similar compositions, these two metallic glasses consist of different clusters, and therefore exhibit different magnetic behaviors. Co63.1B27Si9.9 metallic glass, based on the Co7B3 cluster, shows good soft magnetic properties with low coercivity smaller than 0.9 A/m, while Co65B24.4Si10.6 metallic glass, based on the Co8B3 cluster, exhibits paramagnetic behavior. The origin of these magnetic behaviors was discussed in view of the electronic structures of the metallic glasses. The results indicate that the model was valid not only for glass forming ability but also for tuning properties dominated by short-range orders.

Soft-ferromagnetic bulk glassy alloys with large magnetostriction and high glass-forming ability

The effect of Dy addition on the glass-forming ability (GFA), magnetostriction as well as soft-magnetic properties and fracture strength in FeDyBSiNb glassy alloys was investigated. In addition to the increase of supercooled liquid region from 55 to 100 K, the addition of Dy is effective in approaching alloy to an eutectic point and increasing the saturation magnetostrction (λs). Accordingly, bulk glassy alloy (BGA) rods with diameters up to 4 mm were produced, which exhibit a large λs as high as 65×10-6. Besides, the BGA system exhibits superhigh fracture strength of 4000 MPa, combined with good soft-magnetic properties.

Fe–Si–B–P–Cu Nanocrystalline Alloy Ribbons With High Saturation Magnetic Flux Density Prepared Using Industrial Materials

Magnetic properties and fine structure of Fe-Si-B-P-Cu nanocrystalline alloy ribbons have been investigated. The Fe84.8(Si,B,P)14Cu1.2 alloy ribbons using industrial materials are produced by a single-roller melt-spinning method in air. The Fe84.8(Si,B,P)14Cu1.2 nanocrystalline alloys exhibit low coercivity Hc of 7-20 A/m in the compositional range of Si=0-2 at% and P=2-8 at% and high saturation magnetic flux density Bs of 1.80 T or more in the compositional range of P=0-4 at%. In particular, Fe84.8Si1B10P3Cu1.2 nanocrystalline alloy annealed at 698 K exhibits both the high Bs of 1.82 T and the low Hc of 7.2 A/m. The iron loss W at 50 Hz of the Fe84.8Si1B10P3Cu1.2 nanocrystalline alloy is much smaller than oriented and nonoriented magnetic steel over the maximum induction Bm range up to 1.7 T. In addition, nanocrystalline structure of the Fe84.8Si1B10P3Cu1.2 alloy exhibits a homogeneous nanocrystalline structure composed of α-Fe grains with 5-20 nm in diameter even using industrial materials. Therefore, the Fe-Si-B-P-Cu nanocrystalline alloy has good soft magnetic properties and a large economical advantage of low material cost by using industrial materials.

Soft Magnetic Co-(TiN) Composite Films Realized within a Wide-Range of Cobalt Content

The effect of Co content on the magnetic properties has been systematically investigated, to obtain high frequency soft magnetic <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">${\rm Co}_{\rm x}-({\rm TiN})_{1-{\rm x}}$</tex></formula> films. The films with Co content more than 73 at.% are perpendicular magnetic, and the films with Co content less than 45 at.% are both soft and super-para magnetic. In a wide-range of Co content ( <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm x}=45$</tex></formula> –73 at.%), the <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">${\rm Co}_{\rm x}-({\rm TiN})_{1-{\rm x}}$</tex></formula> nanogranular films show good soft magnetic properties, with coercivity as low as 4 Oe and magnetization around 6–12 kG. The permeability of the films is as high as about 400 and the resonance frequency is around 1 GHz. The films exhibit good thermal stability with the low coercivity of about 5 Oe even after the annealing at 500 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$^{\circ}$</tex> </formula> C, which is very important in viewpoint of application like a CMOS-compatible fabrication technology.

Formation, Crystallization Behavior, and Soft Magnetic Properties of FeCSiBP Bulk Metallic Glass Fabricated Using Industrial Raw Materials

Formation of pseudo-binary Fe-C-Si-B-P bulk metallic glasses (BMGs) with good glass-forming ability (GFA) and soft magnetic properties prepared using industrial pig-iron and P-Fe alloys as raw materials was investigated. It was found that the GFA could be enhanced by tuning the content of carbon, and fully glassy rods with a maximum diameter of 2 mm were obtained in the Fe77.3C5.9Si3.3B4.8P8.7 alloy. The crystallization behavior and its effects on the soft magnetic properties of the Fe77.3C5.9Si3.3B4.8P8.7 alloy were analyzed. The superior magnetic properties, coupled with large GFA and low cost of raw materials, make the current Fe-based BMGs promising for potential applications in electric industries.

Development of the Large Scanning Mirror Using Fe-Based Metallic Glass Ribbon

In order to achieve the large scanning angle without mechanical failure during actuation, the micro-mirror structure was fabricated using Fe-based metallic glass (MG) ribbon. High values of mechanical strength and elastic strain limit are desired for the torsion bar for providing high performance of the mirror, including large tilting angle and good stability. MG materials guarantee superior value of elastic strain limit and fracture toughness resulting from its amorphous structure without line defects like dislocations and grain boundaries. We chose Fe-base MG material for mirror actuation according to its good soft magnetic properties and simple structure without any further step of integration of magnetic material. Millimeter-size mirror device was successfully fabricated by laser machining techniques from Fe-based MG ribbon. Extremely large optical tilting angle of exceeding 100° was obtained on activation of the mirror by magnetic force when electrical current of 100 mA was applied. Large tilting angle of the mirror is due to the torsion bar which was fabricated with Fe-based MG material that has large elastic strain limit and high fracture toughness.

Development of the Large Scanning Mirror Using Fe-Based Metallic Glass Ribbon

In order to achieve the large scanning angle without mechanical failure during actuation, the micro-mirror structure was fabricated using Fe-based metallic glass (MG) ribbon. High values of mechanical strength and elastic strain limit are desired for the torsion bar for providing high performance of the mirror, including large tilting angle and good stability. MG materials guarantee superior value of elastic strain limit and fracture toughness resulting from its amorphous structure without line defects like dislocations and grain boundaries. We chose Fe-base MG material for mirror actuation according to its good soft magnetic properties and simple structure without any further step of integration of magnetic material. Millimeter-size mirror device was successfully fabricated by laser machining techniques from Fe-based MG ribbon. Extremely large optical tilting angle of exceeding 100° was obtained on activation of the mirror by magnetic force when electrical current of 100 mA was applied. Large tilting angle of the mirror is due to the torsion bar which was fabricated with Fe-based MG material that has large elastic strain limit and high fracture toughness.

Friction stir welding of metallic glass

Like amorphous metal, metallic glass has characteristics, including high strength and toughness, high corrosion resistance and good soft magnetic properties, that crystalline metals do not have1. I...

Fe76Si9.6B8.4P6 glassy powder soft-magnetic cores with low core loss prepared by spark-plasma sintering

Abstract Large glassy alloy discs (12 mm diameter, 1 mm thickness) of high relative density (∼98%) were prepared by spark plasma sintering. The bulk magnetic cores (12 mm outer diameter, 6 mm inner diameter, 1 mm thickness) exhibit good soft magnetic properties: saturation magnetization is 1.44 T, coercivity is 31 A/m, and effective permeability at 1 kHz is 1320. They also exhibit much lower loss than a silicon steel core; core loss at 10 kHz and maximum induction of 0.2 T is only 81.7 W/kg.