Thermal stability of electrodeposited soft-magnetic iron alloy layers

In this work, we demonstrate the capability of a dual ion beam sputtering method to obtain iron nitride thin films, FeN x , in a wide composition range (0.1 < x < 0.5) and structures (α , γ , ε, ζ , γ and γ ) by controlling the deposition conditions (i.e. deposition rate, flux and energy of the assisting nitrogen ions and substrate temperature). The average composition of the films has been determined by resonant RBS to enhance the nitrogen signal, whereas the structural characterization and the phase identification have been carried out by X-ray diffraction (XRD) and Mössbauer spectroscopy. We present a thorough and complementary analysis of the XRD and Mössbauer data as a function of the composition of the film for all the iron nitride phases. Furthermore, it is shown that the iron Auger parameter (AP) increases up to 0.8 eV with respect to that for pure α-Fe when the nitrogen concentration increases up to 46 at.% (i.e. γ and γ phases) so that it might serve to analyze samples of unknown composition.

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“…phase diagram at low temperatures, [1] i.e. α -Fe x(x≥8) N, γ -Fe 4 N, ε-Fe x(3≤x<2) N, ζ -Fe 2 N and the cubic γ -FeN and γ -FeN.…”

Section: X-ray Diffraction and Integral Conversion Electron Mössbauermentioning

confidence: 99%

“…The Fe-N system shows a very complex phase diagram [1] and that the iron nitrides can exist in many different phases with different structures and properties. The nitrogen-poor phases, i.e.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of iron nitrides. An XRD, Mössbauer, RBS and XPS characterization

Prieto

Marco

Sanz

2008

Surface & Interface Analysis

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“…Because of the promising magnetic properties observed in thin films, efforts to synthesize bulk samples of the tetragonal 𝛼′′-Fe 16 N 2 phase have also been made. [8][9][10] In the 𝛼′′-Fe 16 N 2 structure, the body-centered cubic (bcc) Fe lattice is expanded into a distorted body-centered tetragonal (bct) lattice due to the presence of N. Close to 500 K, the tetragonal 𝛼′′-Fe 16 N 2 phase decomposes into α-Fe and Fe 4 N phases, 11 making the thermal stability one of the major issues for its synthesis and application. It has been shown that adding a small amount of third elements, such as Co, Mn, or Ti, can stabilize the 𝛼′′-Fe 16 N 2 phase in thin film samples.…”

mentioning

confidence: 99%

Large magnetic anisotropy predicted for rare-earth-free Fe16−xCoxN2
Zhao
¹
,
Wang
²
,
Yao
³

et al. 2016
Phys. Rev. B
51
4
17
0
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Structures and magnetic properties of Fe 16-x Co x N 2 are studied using adaptive genetic algorithm and first-principles calculations. We show that substituting Fe by Co in Fe 16 N 2 with Co/Fe ratio ≤ 1 can greatly improve the magnetic anisotropy of the material. The magnetocrystalline anisotropy energy from first-principles calculations reaches 3.18 MJ/m 3 (245.6 μeV per metal atom) for Fe 12 Co 4 N 2 , much larger than that of Fe 16 N 2 and is one of the largest among the reported rare-earth free magnets. From our systematic crystal structure searches, we show that there is a structure transition from tetragonal Fe 16 N 2 to cubic Co 16 N 2 in Fe 16-x Co x N 2 as the Co concentration increases, which can be well explained by electron counting analysis. Different magnetic properties between the Fe-rich (x ≤ 8) and Co-rich (x > 8) Fe 16-x Co x N 2 is closely related to the structural transition.

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“…38−40 Based on the Fe−N phase diagram, the γ′-Fe 4 N phase forms at the temperature range from 200 to 680 °C. 41 As proposed by the Lehrer diagram, the most stable iron nitride phase could be modified by tuning the nitriding potential that is controlled by the partial pressure of hydrogen and ammonia gas and the nitridation temperature. 42 Thus, different iron nitride phases are obtained using the gas nitridation process, such as α″-Fe 16 N 2 , γ′-Fe 4 N, γ-FeN, ε-Fe-3 N, and so forth.…”

Section: Introductionmentioning

confidence: 99%

Irregularly Shaped Iron Nitride Nanoparticles as a Potential Candidate for Biomedical Applications: From Synthesis to Characterization

Saha

et al. 2020

ACS Omega

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Magnetic nanoparticles (MNPs) have been extensively used in drug/gene delivery, hyperthermia therapy, magnetic particle imaging (MPI), magnetic resonance imaging (MRI), magnetic bioassays, and so forth. With proper surface chemical modifications, physicochemically stable and nontoxic MNPs are emerging contrast agents and tracers for in vivo MRI and MPI applications. Herein, we report the high magnetic moment, irregularly shaped γ′-Fe4N nanoparticles for enhanced hyperthermia therapy and T2 contrast agent for MRI application. The static and dynamic magnetic properties of γ′-Fe4N nanoparticles are characterized by a vibrating sample magnetometer (VSM) and a magnetic particle spectroscopy (MPS) system, respectively. Compared to the γ-Fe2O3 nanoparticles, γ′-Fe4N nanoparticles show at least three times higher saturation magnetization, which, as a result, gives rise to the stronger dynamic magnetic responses as proved in the MPS measurement results. In addition, γ′-Fe4N nanoparticles are functionalized with an oleic acid layer by a wet mechanical milling process. The morphologies of as-milled nanoparticles are characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), and nanoparticle tracking analyzer (NTA). We report that with proper surface chemical modification and tuning on morphologies, γ′-Fe4N nanoparticles could be used as tiny heating sources for hyperthermia and contrast agents for MRI applications with minimum dose.

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Thermal stability of electrodeposited soft-magnetic iron alloy layers

Cited by 4 publications

References 0 publications

Synthesis and characterization of iron nitrides. An XRD, Mössbauer, RBS and XPS characterization

Synthesis and characterization of iron nitrides. An XRD, Mössbauer, RBS and XPS characterization

Large magnetic anisotropy predicted for rare-earth-free Fe16−xCoxN2
Zhao
¹
,
Wang
²
,
Yao
³

et al. 2016
Phys. Rev. B
51
4
17
0
View full text Add to dashboard Cite

Irregularly Shaped Iron Nitride Nanoparticles as a Potential Candidate for Biomedical Applications: From Synthesis to Characterization

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Thermal stability of electrodeposited soft-magnetic iron alloy layers

Cited by 4 publications

References 0 publications

Synthesis and characterization of iron nitrides. An XRD, Mössbauer, RBS and XPS characterization

Synthesis and characterization of iron nitrides. An XRD, Mössbauer, RBS and XPS characterization

Large magnetic anisotropy predicted for rare-earth-free Fe16−xCoxN2Zhao1, Wang2, Yao3 et al. 2016Phys. Rev. B514170View full textAdd to dashboardCite

Irregularly Shaped Iron Nitride Nanoparticles as a Potential Candidate for Biomedical Applications: From Synthesis to Characterization

Contact Info

Product

Resources

About

Large magnetic anisotropy predicted for rare-earth-free Fe16−xCoxN2
Zhao
¹
,
Wang
²
,
Yao
³

et al. 2016
Phys. Rev. B
51
4
17
0
View full text Add to dashboard Cite