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Title: Synthesis of magnetic Fe-based bulk metallic glasses starting from the Fe-Cr-Co system

Abstract

The glass-forming ability of Fe-based bulk metallic glasses is strongly correlated with the amount of metalloids they contain. Starting from a ferromagnetic and ductile Fe-based metallic glass of composition (Fe{sub 0.582}Co{sub 0.418}){sub 80}Cr{sub 10}Zr{sub 10}, we were able to produce several bulk metallic glasses by alloying titanium and boron. The resulting alloys of composition [(Fe{sub 0.582}Co{sub 0.418}){sub 0.81}Cr{sub 0.10}Zr{sub 0.07}Ti{sub 0.02}]{sub 100-x}B{sub =} x (x=10-20 at. %) exhibit a critical casting thickness of 0.5 mm, a wide undercooled liquid region {delta}T{sub x}(=T{sub x}-T{sub g}) of 16-84 K, and ferromagnetic properties. dc magnetization measurements show an inverted hysteresis at room temperature, and small-angle neutron scattering on the [(Fe{sub 0.582}Co{sub 0.418}){sub 0.81}Cr{sub 0.10}Zr{sub 0.07}Ti{sub 0.02}]{sub 90}B{sub 10} bulk metallic glass reveals a power-law dependence of the differential scattering cross-section. The latter indicates a pronounced short-range order with a surface fractal dimension of 2.5. A splat-cooled sample of the same composition does not reveal this pronounced short-range order, but still an inverted hysteresis. From the scaling behavior of the magnetization curves, measured at different temperatures between 50 and 300 K for the splat-cooled sample, we find that an antagonistic internal magnetic field is present in this material. The resulting inverted hysteresis is presumablymore » caused by interacting superparamagnetic and blocked regions.« less

Authors:
; ;  [1]
  1. Laboratory of Metal Physics and Technology, Department of Materials, ETH Zurich, Wolfgang-Pauli-Strasse 10, 8093 Zurich (Switzerland)
Publication Date:
OSTI Identifier:
20884968
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 101; Journal Issue: 1; Other Information: DOI: 10.1063/1.2407268; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; BORON ALLOYS; CHROMIUM ALLOYS; COBALT ALLOYS; DIFFERENTIAL CROSS SECTIONS; FERROMAGNETIC MATERIALS; HYSTERESIS; IRON ALLOYS; MAGNETIC FIELDS; MAGNETIZATION; METALLIC GLASSES; NEUTRON DIFFRACTION; SMALL ANGLE SCATTERING; SUPERPARAMAGNETISM; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0013-0065 K; TEMPERATURE RANGE 0065-0273 K; TEMPERATURE RANGE 0273-0400 K; TITANIUM ALLOYS; VITRIFICATION; ZIRCONIUM ALLOYS

Citation Formats

Mastrogiacomo, Giovanni, Kradolfer, Juerg, and Loeffler, Joerg F. Synthesis of magnetic Fe-based bulk metallic glasses starting from the Fe-Cr-Co system. United States: N. p., 2007. Web. doi:10.1063/1.2407268.
Mastrogiacomo, Giovanni, Kradolfer, Juerg, & Loeffler, Joerg F. Synthesis of magnetic Fe-based bulk metallic glasses starting from the Fe-Cr-Co system. United States. doi:10.1063/1.2407268.
Mastrogiacomo, Giovanni, Kradolfer, Juerg, and Loeffler, Joerg F. Mon . "Synthesis of magnetic Fe-based bulk metallic glasses starting from the Fe-Cr-Co system". United States. doi:10.1063/1.2407268.
@article{osti_20884968,
title = {Synthesis of magnetic Fe-based bulk metallic glasses starting from the Fe-Cr-Co system},
author = {Mastrogiacomo, Giovanni and Kradolfer, Juerg and Loeffler, Joerg F.},
abstractNote = {The glass-forming ability of Fe-based bulk metallic glasses is strongly correlated with the amount of metalloids they contain. Starting from a ferromagnetic and ductile Fe-based metallic glass of composition (Fe{sub 0.582}Co{sub 0.418}){sub 80}Cr{sub 10}Zr{sub 10}, we were able to produce several bulk metallic glasses by alloying titanium and boron. The resulting alloys of composition [(Fe{sub 0.582}Co{sub 0.418}){sub 0.81}Cr{sub 0.10}Zr{sub 0.07}Ti{sub 0.02}]{sub 100-x}B{sub =} x (x=10-20 at. %) exhibit a critical casting thickness of 0.5 mm, a wide undercooled liquid region {delta}T{sub x}(=T{sub x}-T{sub g}) of 16-84 K, and ferromagnetic properties. dc magnetization measurements show an inverted hysteresis at room temperature, and small-angle neutron scattering on the [(Fe{sub 0.582}Co{sub 0.418}){sub 0.81}Cr{sub 0.10}Zr{sub 0.07}Ti{sub 0.02}]{sub 90}B{sub 10} bulk metallic glass reveals a power-law dependence of the differential scattering cross-section. The latter indicates a pronounced short-range order with a surface fractal dimension of 2.5. A splat-cooled sample of the same composition does not reveal this pronounced short-range order, but still an inverted hysteresis. From the scaling behavior of the magnetization curves, measured at different temperatures between 50 and 300 K for the splat-cooled sample, we find that an antagonistic internal magnetic field is present in this material. The resulting inverted hysteresis is presumably caused by interacting superparamagnetic and blocked regions.},
doi = {10.1063/1.2407268},
journal = {Journal of Applied Physics},
number = 1,
volume = 101,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • Bulk metallic glasses consisting of Fe, Mo, Cr, C, B, and Er have been investigated by x-ray photoelectron spectroscopy, aimed to elucidate the local atomic structure of the amorphous phase. In order to examine the electronic properties of this class of material, photon energy dependent measurements in combination with argon-ion irradiation were employed to identify and separate surface and bulk contributions to the spectra. The core levels suggest the presence of a carbon-rich surface layer with oxidized boron and metals, and metal carbides and borides in the bulk. Exposure to molecular oxygen and annealing experiments probe the chemical reactivity ofmore » the material. Formation of boron oxides at comparably low temperatures (300 deg. C) might have consequences for the stability of the amorphous phase. We observe variations in binding energy of the Fe 3p core level with respect to the alloy composition, which indicate changes in the chemical state of iron.« less
  • Mechanical properties and glass transition temperatures (T{sub g}) of Fe-Cr-Mo-P-C-B bulk metallic glasses containing up to 27 at. % metalloids have been studied. The shear modulus (G) is found to decrease with increasing metalloid content and a maximum plastic strain of {approx}3% is obtained, despite the increase in the number of strong metal-metalloid bonds. Also, T{sub g} increases with the decrease in G, in contrast to usual behavior. By employing first-principles calculations, the results are discussed in light of atomic bonding and connectivity in the amorphous network. The findings are relevant to understanding ductility and glass transition of metallic glasses.
  • The effects of heavy rare earth (RE) additions on the Curie temperature (T{sub C}) and magnetocaloric effect of the Fe-RE-B-Nb (RE = Gd, Dy and Ho) bulk metallic glasses were studied. The type of dopping RE element and its concentration can easily tune T{sub C} in a large temperature range of 120 K without significantly decreasing the magnetic entropy change (ΔS{sub M}) and refrigerant capacity (RC) of the alloys. The observed values of ΔS{sub M} and RC of these alloys compare favorably with those of recently reported Fe-based metallic glasses with enhanced RC compared to Gd{sub 5}Ge{sub 1.9}Si{sub 2}Fe{sub 0.1}. The tunable T{submore » C} and large glass-forming ability of these RE doped Fe-based bulk metallic glasses can be used in a wide temperature range with the final required shapes.« less
  • Fe{sub 81.5}Cr{sub 4.5}B{sub 14} metallic glass ribbons were prepared by melt spinning technique without magnetic field and in longitudinal or transversal magnetic field of 13--15 kA/m. From these ribbons the 59--60 mm long and about 4 mm wide strips were cut. Ultrasound velocities at constant magnetic field and at constant magnetic induction were investigated. For comparison the results for the Fe{sub 80}Cr{sub 4.3}B{sub 15.7} metallic glass ribbon prepared without magnetic field (WM) are presented.
  • The aim of the investigations was to determine the influence of the magnetic and thermal treatments and of the magnetic bias field on the ultrasound velocities {ital c} in Fe{sub 79}Cr{sub 6.6}B{sub 14.4} metallic glass ribbons prepared in a longitudinal or transverse magnetic field. The values of {ital c} for the points near the demagnetization state and near the magnetic saturation were changing from about 4550--4600 m/s for as-cast state to 4700--4900 m/s after the last annealing at 360 {degree}C. After the annealings between 280 and 350 {degree}C the minimum values of {ital c} dropped to 4360 m/s and thismore » phenomenon is connected with the {Delta}{ital E} effect and and with increasing of the magnetomechanical coupling coefficient {ital k} with annealing (up to about 0.25 after annealing at 350 {degree}C from {ital k}{sub {ital m}} = 0.1 for as-cast state). This material may be useful in magnetostrictive delay line applications.« less