Soft Magnetic Behavior Research Articles

Soft Ferromagnetic Properties of Half-Metallic Mn2CoAl Heusler Alloy Nanoparticles for Spintronics Applications

The ternary full Heusler alloy Mn2CoAl nanoparticles were synthesized by using co-precipitation technique. The as-prepared sample was observed for amorphous nature and further increased at various annealing temperatures (like 700 °C, 800 °C and 900 °C) in argon gas atmosphere for 5 h. X-ray diffraction studies were performed, and the pattern confirms the formation of Hg2CuTi-type structure of the XA or Xα disorder structure. Williamson-Hall plot (W-H plot) was used to find the uniform deformation model so as to get low value of strain-induced broadening. The presence of Mn2CoAl with the particle size ≈ 50 nm was obtained from high-resolution scanning electron microscopy (HR-SEM), and the elemental analysis study confirms the presence of Mn, Co, and Al. UV-Visible absorption spectrum shows the wide absorption peak at 470 nm and the estimated band gap energy value at Eg = 0.8 eV (from Tauc plot) for 900 °C annealed sample. Synthesized Mn2CoAl nanoparticles induced ferromagnetic behavior due to composition deviation and as a result displayed low coercivity of soft magnetic behavior. Half-metallic ferromagnetic Heusler alloys have a wide range of applications from medical imaging to data storage, and also it has profound spintronics applications.

A synthesis of polyethylene glycol (PEG)-coated magnetite Fe3O4 nanoparticles and their characteristics for enhancement of biosensor

The magnetite Fe3O4 nanoparticles were synthesized by using chemical co-precipitation method and these nanoparticles were successfully coated by polyethylene glycol (PEG) with variation concentrations of PEG. The magnetite Fe3O4 nanoparticles used as a bimolecular label (nano-tags), exhibiting a soft magnetic behavior with magnetization (Ms) of 77.16 emu g−1 and coercivity (Hc) of 50 Oe respectively. The polyethylene glycol (PEG) was used as a biocompatible polymer. The x-ray diffraction (XRD) patterns of the Fe3O4 showed that Fe3O4 was well crystallized. It also confirmed the existence of invers spinel. The diffraction peak of 35.4° was used to calculate the crystallite size. The estimation of Fe3O4 average crystallite size is 12 nm, while the PEG-coated Fe3O4 nanoparticles is 8.6 nm. The transmission electron microscopy (TEM) images of Fe3O4 showed that the morphology of magnetite Fe3O4 nanoparticle is spherical in shape with uniform grain size and good dispersibility despite the agglomeration it found in some place. The addition of PEG can decrease the agglomeration and reduce the particle size. The existence of PEG layer on Fe3O4 was confirmed by Fourier transform infrared (FTIR) spectroscopy. The result of Vibrating Sample Magnetometer (VSM) showed that saturation magnetization (Ms) of Fe3O4 nanoparticles decreased from 77.16 to 37.15 emu g−1 with the increase of PEG weight from 0% to 50%. Such Fe3O4 nanoparticles with favorable size and tunable magnetic properties are promising biosensor applications.

The Effects of Annealing after Equal Channel Angular Extrusion (Ecae) on Mechanical and Magnetic Properties of 49Fe-49Co-2V Alloy

Equal channel angular extrusion (ECAE) of 49Fe-49Co-2V, also known as Hiperco® 50A or Permendur-2V, greatly improves the strength and ductility of this alloy, while sacrificing soft magnetic performance. ECAE Hiperco specimens were subjected to post-ECAE annealing in order to improve soft magnetic properties. The microstructure, mechanical properties, and magnetic performance are summarized in this study. Annealing begins above 650°C and a steep decline in yield strength is observed for heat treatments between 700 and 840°C due to grain growth and the Hall-Petch effect, although some strength benefit is still observed in fully annealed ECAE material compared to conventionally processed bar. Soft magnetic properties were assessed through B-H hysteresis curves from which coercivity (Hc) values were extracted. Hc decreases rapidly with annealing above 650°C as well, i.e. improved soft magnetic behavior. The observed trend is attributed to annealing and grain growth in this temperature regime, which facilitates magnetic domain wall movement. The coercivity vs. grain size results generally follow the trend predicted in the literature. The magnetic behavior of annealed ECAE material compares favorably to conventional bar, possibly due to mild crystallographic texturing which enhances properties in the post-ECAE annealed material. Overall, this study highlights a definitive tradeoff between mechanical and magnetic properties brought about by post-ECAE annealing and grain growth. ®Hiperco is a tradename of Carpenter Technology Corp., Reading, PA.

Ar ion irradiation effect on the soft magnetic performance of Fe-based amorphous alloys

We investigate the effect of Ar ion irradiation on the microstructure and soft magnetic behaviors of Fe80CoxB14-xSi2P3Cu1 (x = 0, 2, 4) amorphous alloys by using X-ray diffraction (XRD), differential scanning calorimetry (DSC) and soft magnetic performance analysis. With increasing Co content, the alloy shows decreasing radiation resistance, i.e., more degree of nanocrystallization induced by irradiation. It is found that after irradiation with fluence of ~9.0 × 1014, the coercivity is reduced from 7.6 A/m to 7.0 A/m, but increases again with further increase of irradiation fluence due to the formation of larger nanosized α-Fe(Co) grains. And with increasing irradiation fluence, the saturation magnetic flux density first decreases slightly from 1.65 T to 1.64 T, and then increases gradually to 1.68 T. Further, the core loss and effective magnetic conductivity were tuned obviously by irradiation, which has been discussed in term of stress relaxation and nanocrystallization.

Ga-substituted Mg-Cd ceramic composites for improving the miniaturization and wideband characteristics of high-frequency antennas

Mg0·8Cd0·2Fe1.9Ga0.1O4 ceramic ferrites were synthesized using a solid-state reaction method at 900, 915, 930 and 945 °C. Crystallization analysis indicated that the change in temperature resulted in obvious changes in the microstructure. SEM images indicated that the grain size increased from 0.8 to 1.8 μm. Elevated saturation magnetization (Ms ≈ 26 emu/g) and reduced coercivity (Hc ≈ 53 Oe) indicated the excellent soft-magnetic behavior of the ceramics. The real part of the permeability correspondingly increased (29–51), and the real part of permittivity showed a slight fluctuation (20–25) with an increase in the temperature. Consequently, an upward bandwidth ratio (BWR ≈ 0.2, 915 °C) and matching characteristic impedance were obtained over a wide frequency range of 1–100 MHz. Additionally, with the low magnetic (tanδμ ~10−2) and dielectric (tanδε ~ 10−4-10−3) tangent values, the proposed materials can act as potential agents for enhancing the bandwidth and miniaturization of antennas operating at high frequencies.

Synthesis and characterization of Co0.4 Fe0.6 thin film alloy

A study of structural and magnetic properties of Co0.4 Fe0.6 thin film alloy on Si (1 0 0) substrate deposited using the DC-magnetic sputtering technique is reported. Grazing Incidence X-ray Diffraction (GI-XRD) is used to study the crystal structure of the thin film alloy. The structural analysis reveals that thin-film alloy has a bcc crystal structure with lattice constant 2.656 Å. The thickness of the thin film alloy is about 30 nm measured from X-ray Reflectivity (XRR) data. Energy Dispersive X-ray Analysis (EDAX) confirms the presence of Co and Fe in the thin film alloy with composition 44.4% Co and 55.6% Fe. Magneto-Optic Kerr Effect (MOKE) technique is used to study the magnetic structure of the thin film alloy. Our results suggest that Co0.4Fe0.6 thin film alloy exhibits soft magnetic behavior. The decrease in the coercive field with the increase of rotation of the substrate may relate to the reduction of the grain size according to Hoffman’s ripple theory or change in preferred crystal orientation. Domain wall motion shows that the magnetization reversal occurs via coherent rotation of spins along the hard axis due to the uniaxial nature of the sample. CoFe alloys find many applications, especially in spintronics.

Influence of annealing temperature on the structural and magnetic properties of FeGaSiB thin films

Understanding the relationship between the structure and magnetic properties of soft magnetic thin films is important in the development of magnetic sensors and electronic devices. This work has systematically studied how the annealing temperature changes the morphology and hence the magnetic properties of 60 nm FeGaSiB thin films. The as-grown and 100 °C annealed films were amorphous/nanocrystalline with soft magnetic properties. As the annealing temperature increased, so did the coercive field of the films, which was found to be due to the formation of polycrystalline grains, with random texture. The grain size increased with increasing annealing temperature, while the Curie Temperature and magnetostriction constant decreased. For the saturation induction, there was a large decrease between the 100 °C annealed film and the 250 °C annealed film, due to the film morphology changing from amorphous to polycrystalline. Thus there is strong correlation between the crystallinity and the soft magnetic behaviour of FeGaSiB films.

Structural and magnetic features of Ce doped Co-Cu-Zn spinel nanoferrites prepared using sol gel self-ignition method

Cerium (Ce) substituted spinel nanocrystalline ferrites with composition Co0.30Cu0.25Zn0.45CexFe2-xO4 with (x = 0.00, 0.025, 0.050, 0.075 and 0.10) were synthesized using sol-gel auto-ignition method. Cerium was substituted to modify the properties of the Co-Cu-Zn spinel nanocrystalline ferrites. Structural, spectral, morphological and magnetic properties of all synthesized ferrites were investigated. Structural parameters such as crystallite size, micro strains, lattice parameters, FWHM and cell volume were calculated from XRD study. Ce undoped and doped nanoferrites revealed the single-phase spinel structure within crystalline sizes range (77.59–109.27) nm. FTIR study revealed the octahedral and tetrahedral bands for all spinel nanoferrites. FESEM images depicted the high agglomerations at x = 0.10 with random shape of the particles. VSM presented the magnetic features in terms of saturation, remanence, squareness ration, coercivity, initial permeability, Bohr magneton and anisotropy constant (K). All these parameters showed increased in values with the increased in the concentrations of Ce in Co-Cu-Zn spinel nanoferrites. Squareness ratio were found (>1) depicted the soft magnetic behavior. All the Ce substituted spinel ferrites are suggested to be utilized for adsorbents in wastewater treatment, recording media and memory devices.

Structural, Morphological and Magnetic Characterization of Sm-substituted Ni-Zn Ferrite

Background: Rare earth materials are known for its salient electrical insulation properties with high values of electrical resistivity. It is expected that the substitution of rare earth ions into spinel ferrites could significantly alter its magnetic properties. In this work, the effect of the addition of Samarium ions on the structural, morphological and magnetic properties of Ni0.5Zn0.5SmxFe2-xO4 (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) synthesized using sol-gel auto combustion technique was investigated. Methods: A series of Samarium-substituted Ni-Zn ferrite nanoparticles (Ni0.5Zn0.5SmxFe2-xO4 where x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by sol-gel auto-combustion technique. Structural, morphological and magnetic properties of the samples were examined through X-Ray Diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and Vibrating Sample Magnetometer (VSM) measurements. Results: XRD patterns revealed single-phased samples with spinel cubic structure up to x= 0.04. The average crystallite size of the samples varied in the range of 41.8 – 85.6 nm. The prepared samples exhibited agglomerated particles with larger grain size observed in Sm-substituted Ni-Zn ferrite as compared to the unsubstituted sample. The prepared samples exhibited typical soft magnetic behavior as evidenced by the small coercivity field. The magnetic saturation, Ms values decreased as the Sm3+ concentration increases. Conclusion: The substituted Ni-Zn ferrites form agglomerated particles inching towards more uniform microstructure with each increase in Sm3+ substitution. The saturation magnetization of substituted samples decreases with the increase of samarium ion concentration. The decrease in saturation magnetization can be explained based on weak super exchange interaction between A and B sites. The difference in magnetic properties between the samples despite the slight difference in Sm3+ concentrations suggests that the properties of the NiZnFe2O4 can be ‘tuned’, depending on the present need, through the substitution of Fe3+ with rare earth ions.

Analysis of structure and magnetic behavior in M-type hexaferrite compounds Sr1−xYxFe10CoTiO19

Herein, we report the synthesis, structure and magnetic properties of Y-substituted CoTi-SrM hexaferrite Sr1−xYxFe10CoTiO19 (0.00 ≤ x ≤ 0.20) through a series of systematical measurements. The single phase of polycrystalline SrM hexaferrites can be obtained within the concentration x ≤ 0.15, and the lattice constants (a and c) show a corresponding variety due to the difference of substituted ionic radius (Δr). Besides, FTIR spectra also give the characteristic features of Fe3+–O2+ intrinsic vibration at tetrahedral and octahedral sites, which further confirm the integrity of M-type hexagonal magnetic structure. The comprehensive magnetic measurements [M(T) and M(H)] indicate a considerable results of temperature and magnetic properties. Especially, Ms can be improved to 79.19 emu/g under the definite substitution, and the soft magnetic behavior can also be preserved because of the fairly low Hcj. On the basis of the analyses in our present work, this substituted hexaferrite exhibits a quite promising candidate for high-frequency multilayer inductors.

Controllable synthesis of 3D spicate Fe36Co64 alloy microstructures as superior cyclicity and magnetically recyclable catalyst for p-nitrophenol reduction

In this letter, a high-efficiency and magnetically recoverable catalysts of novel Fe36Co64 alloy microstructures (AMSs) with 3D spicate shapes were synthesized by solvothermal method. The 3D spicate Fe36Co64 AMSs displayed a high saturation magnetization (163.5 emu/g) and exhibited soft magnetic behavior. The obtained 3D spicate Fe36Co64 AMSs were used as cyclicity and magnetically recyclable catalysts for catalytic hydrogenation of p-nitrophenol into p-aminophenol.

Study on magnetoelectric properties of Ni0.5Zn0.5Fe2O4/Ba0.8Sr0.2TiO3 composite ceramics based on Bi2O3 as combustion aid

Ni0.5Zn0.5Fe2O4/Ba0.8Sr0.2TiO3 (NZFO/BST) composite ceramics with different additions of Bi2O3 (0%, 1%, 3%, and 5% wt) were synthesized via the solid-phase sintering method. XRD analysis indicates that the composite ceramics show bi-phase structure, without apparent secondly phases can be observed. SEM images show that all the specimens have relative dense structure, the grain size is in the range 1–2 μm. A certain amount of Bi2O3 is beneficial to grain growth, the average grain size of NZFO/BST ceramics increases from 179 to 297 nm when the concentration of Bi2O3 is 0 and 3%, respectively. EDS results indicate that the distribution of NZFO phase and BST phase is not uniform. The sample NZFO/BST-3%Bi2O3 not only has the largest dielectric constant (er) in the whole temperature range (25–500 °C), but also presents the smallest dielectric loss (tanδ) at high temperature region (> 400 °C), and the maximum tanδ value is less than 0.4 for all the samples, indicating excellent dielectric performance. Compared with other samples, the specimen NZFO/BST-3%Bi2O3 has the largest remnant polarization (~ 1.14 μC/cm2). The sample NZFO/BST-3%Bi2O3 has the largest leakage current density, while the ceramic NZFO/BST-5%Bi2O3 presents the opposite behavior, the value of leakage current of the sample NZFO/BST-3%Bi2O3 is about 7 times larger than that of the specimen NZFO/BST-5%Bi2O. All the composite ceramics show soft magnetic behavior, since Bi2O3 is a non-magnetic phase, addition of Bi2O3 will dilute the magnetic moment per unit volume so as to decrease the magnetic properties of the ceramics. The sample NZFO/BST-3%Bi2O3 has the second largest saturation magnetization (Mr) of 11.27 emu/g and the smallest coercive field (HC) ~ 3.54 Oe. All the samples show strong magnetoelectric coupling effect, the highest magnetoelectric coupling coefficient is ~ 47 Vcm−1Oe−1, which was obtained in the sample without addition of Bi2O3. In short, the addition of Bi2O3 not only affects the structure of composite ceramics, but also plays an important role in affecting the magnetoelectric performance.

Solution Synthesis of Layered van der Waals (vdW) Ferromagnetic CrGeTe3 Nanosheets from a Non-vdW Cr2Te3Template.

CrGeTe3 has recently emerged as a new class of two-dimensional (2D) materials due to its intrinsic long-range ferromagnetic order. However, almost all the reported synthesis methods for CrGeTe3 nanosheets are based on the conventional mechanical exfoliation from single-crystalline CrGeTe3, which is prepared by the complicated self-flux technique. Here we report a solution-processed synthesis of CrGeTe3 nanosheets from a non-van der Waals (vdW) Cr2Te3 template. This structure evolution from non-vdW to vdW is originated from the substitution of Ge atoms on the Cr sites surrounded by fewer Te atoms in the Cr2Te3 lattice due to their smaller steric hindrance and lower energy barrier. These CrGeTe3 nanosheets present regular hexagonal structures with a diameter larger than 1 μm and excellent stability. They exhibit soft magnetic behavior with a Curie temperature lower than 67.5 K. This non-vdW to vdW synthesis strategy promotes the development of CrGeTe3 in ferromagnetism while providing an effective route to synthesize other 2D materials.

Exchange correlation and magnetism in bcc Fe[formula omitted]Ni[formula omitted] alloy

We investigate the magnetism and the electronic structure of body centred cubic, Fe0.8Ni0.2 alloy. While the magnetic moment of pure Fe and the alloy in bcc phase are almost similar, the hysteresis loop exhibits soft magnetic behavior. Transport measurements exhibit hysteresis in cooling and heating cycles indicating possibilities of structural change in the alloy. Photoemission results exhibit signature of correlation induced effect in the core level spectra. The interaction parameters associated to the Ni electronic states are found to be influenced by the alloying presumably due to disorder induced effect. Fe 2s core level spectra exhibit three distinct peaks due to exchange splitting and correlation of Fe 3d electrons. The exchange splitting seems to remain unchanged in the temperature range studied in the alloy. Evidently, electron correlation and disorder is important to derive the complex electronic properties of this material. Our results establish that the magnetism and transport properties of Fe can be influenced significantly keeping the Fe moment unchanged via alloying with Ni, which is important for the applications of this material. Further studies are required to understand the resistivity anomaly and soft magnetism of this alloy.

Influence of Milling Time on the Homogeneity and Magnetism of a Fe70Zr30 Partially Amorphous Alloy: Distribution of Curie Temperatures.

In this work, the mechanically alloyed Fe70Zr30 (at. %) composition has been used to study the influence of milling time on its homogeneity and magnetic properties. The microstructure and Fe environment results show the formation of an almost fully amorphous alloy after 50 h of milling in a mixture of pure 70 at. % Fe and 30 at. % Zr. The soft magnetic behavior of the samples enhances with the increase of the milling time, which is ascribed to the averaging out of the magnetocrystalline anisotropy as the crystal size decreases and the amorphous fraction increases. The formation of a non-perfectly homogenous system leads to a certain compositional heterogeneity, motivating the existence of a distribution of Curie temperatures. The parameters of the distribution (the average Curie temperature, , and the broadening of the distribution, ) have been obtained using a recently reported procedure, based on the analysis of the approach towards the saturation curves and the magnetocaloric effect. The decrease of and the increase of with the milling time are in agreement with the microstructural results. As the remaining α-Fe phase decreases, the amorphous matrix is enriched in Fe atoms, enhancing its magnetic response.

Development and characterization of new Co–Fe–Hf–B bulk metallic glass with high thermal stability and superior soft magnetic performance

Cobalt-based metallic glasses have stimulated widespread interest due to their excellent mechanical properties and soft magnetic behavior. In the present work, a new Co51Fe15Hf6.5B27.5 glassy alloy was designed based on the ternary eutectic Co66Hf6.5B27.5 composition and its microstructure, thermal behavior and magnetic properties were examined. Partial substitution of Co with Fe in the new alloy systematically changes the crystallization behavior, enhances the fraction of complex (Co,Fe)21Hf2B6 phase upon crystallization and increases the extension of the supercooled liquid region from 26 K to 48 K. The improved thermal stability is in line with an increased activation energy of crystallization from 523 ± 20 kJ/mol for the Co66Hf6.5B27.5 glass to 573 ± 20 kJ/mol, corresponding to the Co51Fe15Hf6.5B27.5 glass. Magnetic studies revealed that the addition of Fe noticeably increases the saturation magnetization, Curie temperature, and slightly increases the coercive force from 19 A m2/kg to 57 A m2/kg, 315 K–515 K and 0.5 A/m to 1.5 A/m, respectively. It was found that the Co51Fe15Hf6.5B27.5 glassy ribbons exhibit a high resistance against milling-induced crystallization under cryogenic condition. The prepared cryomilled glassy particles show adequate thermal stability and thermoplastic forming ability for hot consolidation into a high density (96%) bulk metallic glass (BMG) with 10 mm diameter. The Co51Fe15Hf6.5B27.5 BMG exhibits a saturation magnetization of 57 A m2/kg, a Curie temperature of 527 K and a very low coercivity of 7 A/m, indicating its superior soft magnetic performance compared to most Co/Fe-based BMGs fabricated via powder metallurgy techniques. The evolution of microstructure, thermal behavior and magnetic properties upon cryomilling, hot consolidation and subsequent annealing was discussed.

Study of structural, magnetic properties and bandgap of spinel Co1−xFe2+xO4 ferrite

Co1−xFe2+xO4 (x = 0.0–0.8) spinel nano ferrite dry gel powders were synthesized by sol gel auto-combustion method. Synthesized samples were investigated by using X-ray diffraction (XRD), magnetic measurements, Ultraviolet–visible (Uv–Vis); Fourier transform infrared (FTIR) spectroscopy. XRD validates the formation of spinel phase, and incorporation of Co, Fe in spinel lattice. Results reveal that compositional variation leads to: i) cationic re-distribution; ii) allowing fine-tuning of bandgap with strong correlation among Bandgap – Fe3+ ions on B-site; iii) changes in degree of inversion; iv) variation of disorder; v) shows better soft magnetic behavior; vi) surface spin disorder leads to reduction of saturation magnetization; vii) observed changes in Debye temperature suggest modification of lattice vibrations.

Auto combustion synthesis using grapefruit extract: photocatalyst and magnetic MgFe2O4-PbS nanocomposites

Magnesium ferrite (MgFe2O4) as a core magnetic nanostructure was synthesized via auto combustion method by using grapefruit extract as a biocompatible and cost-effective material. Then flower and star-like PbS were synthesized using thioglycolic acid as a sulfur source without using any chemical template. After that for preparation of magnetic and photocatalyst MgFe2O4-PbS nanocomposites, lead sulfide were coated on the magnetic core by hydrothermal procedure. Morphology of the prepared products was estimated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), also X-ray diffraction (XRD) pattern show purity and phase of the product. Fourier transforms infrared (FT-IR) spectroscopy show vibration modes of the bonds. Vibrating sample magnetometer (VSM) illustrated that magnesium ferrite nanoparticles have a soft magnetic behaviour with 18 emu/g magnetization and coercivity about 90Oe. The photocatalytic behaviour of MgFe2O4-PbS nanocomposites were examined using the degradation of two various azo dyes acid brown and acid violet under visible light irradiation. This magnetic photocatalyst can easily separate from water with an external magnetic field and can be used under solar irradiation.

Influence of zinc and cadmium co-doping on optical and magnetic properties of cobalt ferrites

Zinc and cadmium based cobalt ferrites ZnxCd0.375-xCo0.625Fe2O4 (where x = 0, 0.075, 0.125, 0.25) were successfully synthesized by a facile co-precipitation technique. Structural, optical and magnetic characteristics of the doped ferrites were systematically analyzed. X-ray Diffraction (XRD) pattern confirmed the formation of cubic spinel structure in all samples. Scanning electron microscopic analysis of surface morphology revealed cubic and spherical shaped ferrite particles. Fourier transform infrared (FTIR) spectroscopy confirmed the existence of metal oxygen (M − O) bonding in the prepared samples. Moreover, the prepared samples exhibited two frequency bands corresponding to phonon vibrational stretching in both octahedral and tetrahedral lattice positions. The optical properties were investigated in detail through photoluminescence (PL) spectroscopy and Raman spectroscopy. The PL spectrum confirmed the strong emission peaks in the ultraviolet to visible region of all the samples. Further, four active Raman modes, associated with cubic spinel structure are identified in all prepared samples. Finally, the magnetic characteristics are evaluated by using vibrating sample magnetometer (VSM) revealing ferrimagnetic and soft magnetic behavior of the samples. As the Zn and Cd co-doping in Co was increased, the Hc was decreased. The magnetic studies show the maximum Hc of 576 Oe for Cd doped cobalt ferrite, and maximum saturation magnetization (Ms) for Zn–Cd doped cobalt ferrite. It is envisaged that the newly prepared Zn–Cd co-doped cobalt ferrite would be appropriate for a number of important applications, for example, magnetic recording devices, sensors, actuators, high-density data storage devices, and biomedical equipments.

Glass forming ability and soft-magnetic properties of Fe-based glassy alloys developed using high phosphorous pig Iron

Glass forming ability (GFA) and soft-magnetic behaviour of melt-spun Fe69C5.5P11.5Mn0.4Si2.3Cr1.8Mo1B8.5 (alloy 2) and Fe68C9P12Mn1Si3Nb2B5, (alloy 3) alloys prepared using high phosphorous pig iron (h-PI, Fe80C14P2.2Mn0.4Si3.4) has been studied. The glass formation, thermo-physical and soft-magnetic properties of the alloys were analyzed for different quenching rates by varying wheel speed as 23, 26, 33, 39 and 43 m/s. The simultaneous incorporation of alloying elements (Cr, Mo, Nb) and metalloids (C, B, P, Si) transforms h-PI to complete glassy alloy, even at low quenching rates. The melt quenching rate influences the thermal parameters and Curie temperature of glassy ribbons in an opposite way. Amongst all, FeCPMnSiCrMoB glassy alloy show superior combination of higher glass transition temperature of 788 K, super cooled region of 34 K, glass Curie temperature of 552 K, coercivity less than 13 A/m and maximum saturation magnetization of 1.1 T. In addition, the annealing treatment at 758 K improves magnetic softness (1.7 A/m) of the alloy by relaxation of quenched-in stresses. The comparison of developed glassy alloy with similar Fe-glassy alloys and SENNTIX type alloys show best combination of thermo-physical and magnetic properties. The glassy alloy prepared using blast furnace high phosphorous pig iron can be used for uniformly gapped soft-magnetic cores.