Synthesis of α″-Fe16N2 foils with an ultralow temperature coefficient of coercivity for rare-earth-free magnets

Liu, Jinming; Guo, Guannan; Zhang, Xiaowei; Zhang, Fan; Ma, Bin; Wang, Jian Ping

doi:10.1016/j.actamat.2019.11.052

Cited by 27 publications

(16 citation statements)

References 43 publications

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“…the magnetic α″Fe 16 N 2 type phase of Fe-Nmartensite has the largest saturation magneticfield strength (2.58 t [18], 2.6-2.8 t [19], 2.83 t [20], 2.9 t [21], 3.1 t [22]) far beyond the iron-cobalt alloy and all other magnetic materials. the α″Fe 16 N 2 can possess even an ultralow positive temperature coefficient of coercivity (within the range from 300 K to 425 K) [23]. to explain the giant saturation magnetization behaviour in α″Fe 16 N 2 , a 'cluster + atom' model was proposed [24].…”

Section: Discovery Of α″-Fe 16 N 2 and Its Large Saturation Magnetizationmentioning

confidence: 99%

Martensitic αʺ-Fe16N2-Type Phase of Non-Stoichiometric Composition: Current Status of Research and Microscopic Statistical-Thermodynamic Model

Radchenko¹,

Gatsenko²,

Lizunov³

et al. 2020

Usp. Fiz. Met.

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The literature (experimental and theoretical) data on the tetragonality of martensite with interstitial–substitutional alloying elements and vacancies are reviewed and analysed. Special attention is paid to the studying the martensitic αʺ-Fe16N2-type phase with unique and promising magnetic properties as an alternative to the rare-earth intermetallics or permendur on the world market of the production of permanent magnets. The period since its discovery to the current status of research is covered. A statistical-thermodynamic model of ‘hybrid’ interstitial–substitutional solid solution based on a b.c.t. crystal lattice, where the alloying non-metal constituents (impurity atoms) can occupy both interstices and vacant sites of the host b.c.c.(t.)-lattice, is elaborated. The discrete (atomic-crystalline) lattice structure, the anisotropy of elasticity, and the ‘blocking’ and strain-induced (including ‘size’) effects in the interatomic interactions are taken into account. The model is adapted for the non-stoichiometric phase of Fe–N martensite maximally ordered by analogy with αʺ-Fe16N2, where nitrogen atoms are in the interstices and at the sites of b.c.t. iron above the Curie point. It is stressed an importance of adequate data on the available (in the literature) temperature- and concentration-dependent microscopic energy parameters of the interactions of atoms and vacancies. The features of varying (viz. non-monotonic decreasing with increasing temperature) the relative concentration of N atoms in the octahedral interstices of b.c.t. Fe, and therefore, the degree of its tetragonality (correlating with this concentration) are elucidated. Within the wide range of varying the total content of introduced N atoms, the ratio of the equilibrium concentration of residual site vacancies to the concentration of thermally activated vacancies in a pure b.c.c. Fe is demonstrated at a fixed temperature.

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Section: Discovery Of α″-Fe 16 N 2 and Its Large Saturation Magnetizationmentioning

confidence: 99%

Martensitic αʺ-Fe16N2-Type Phase of Non-Stoichiometric Composition: Current Status of Research and Microscopic Statistical-Thermodynamic Model

Radchenko¹,

Gatsenko²,

Lizunov³

et al. 2020

Usp. Fiz. Met.

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“…The XRD pattern of starting IONPs matches well with the PDF, indicating that the starting materials are γ-Fe 2 O 3 . These IONPs are then reduced by hydrogen gas to get rid of oxygen and create preferable microstructures for the following nitriding process. − After nitriding, the XRD patterns show that the main phase is γ′-Fe 4 N. Thus, γ′-Fe 4 N nanoparticles are successfully synthesized by the gas nitriding approach. The ball-and-stick models of γ-Fe 2 O 3 and γ′-Fe 4 N are shown in Figure d to provide a brief view of how the crystal structure changes from γ-Fe 2 O 3 to reduced Fe and synthesized γ′-Fe 4 N.…”

Section: Resultsmentioning

confidence: 99%

Stable and Monodisperse Iron Nitride Nanoparticle Suspension for Magnetic Diagnosis and Treatment: Development of Synthesis and Surface Functionalization Strategies

Liu

Saha

et al. 2021

ACS Appl. Nano Mater.

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The past decade has seen tremendous progress in the synthesis and surface functionalization of iron oxide nanoparticles (IONPs) for a variety of biomedical applications. However, there is still a growing demand on magnetic nanoparticles with higher magnetic moments for more sensitive diagnosis and lower dose treatments in magnetic bioassays, imaging, and therapies. In view of this need, the γ′-Fe 4 N nanoparticle, with around 3 times higher saturation magnetizations than IONPs, becomes one promising alternative for these applications. However, the large and non-uniformly distributed sizes of γ′-Fe 4 N nanoparticles hinder the biomedical applications. These synthesized γ′-Fe 4 N nanoparticles are not suitable for biomedical applications at the current stage. Herein, we have developed and demonstrated a wet ball milling method along with different surface-active media to produce ultrastable, monodispersed, uniformly sized, and sub-100 nm γ′-Fe 4 N nanoparticles in solvents. Different standard characterization methods such as transmission electron microscopy, nanoparticle tracking analysis, and Fourier-transform infrared spectroscopy are carried out to measure the physicochemical properties of these surface-functionalized γ′-Fe 4 N nanoparticles. It is confirmed that the functional chemical groups have been successfully anchored on our purified sub-100 nm γ′-Fe 4 N nanoparticles, which allows for convenient subsequent conjugation of proteins, nucleic acids, and drugs for future in vitro and in vivo biomedical applications.

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“…As can be seen, the impedance curves can be divided into two parts: a semicircle in the high‐frequency region which represents the combined surface film and charge transfer resistance at the electrode/electrolyte interface and a sloping line in the low‐frequency region which indicates lithium ion diffusion in the solid electrode . It is obvious that two change regularities can be extracted from the data in Table : i) Regardless of NCA or BiPO 4 ‐coated NCA, the R ct value augments with the increase of cycle number and the extension of the charge and discharge cut‐off voltage.…”

Section: Resultsmentioning

confidence: 99%

Effect of Voltage Range and BiPO₄ Coating on the Electrochemical Properties of LiNi_0.8Co_0.15Al_0.05O₂

Liu

Guo²,

Qin

et al. 2018

ChemistrySelect

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BiPO4‐coated LiNi0.8Co0.15Al0.05O2 (NCA) cathode material is prepared by a precipitation method. Scanning electron microscope and X‐ray diffraction results demonstrate that the morphology and structure of NCA are not affected by BiPO4 layer. Transmission electron microscopy analysis indicates that the thickness of the layer is about 10 nm. Electrochemical properties of NCA and BiPO4‐coated NCA are investigated in different voltage ranges. The results show that the wider the charge and discharge cut‐off voltage is, the larger the specific capacity is, with the initial discharge capacity of 325.0 mAh g−1 within the voltage of 1.5‐4.8 V. The most significant discovery is the charge platform at 2.3‐2.5 V and the discharge platform at around 1.7 V, which accounts for the high capacity properties of NCA. Furthermore, the existence of BiPO4 coating helps to enhance the cycle performance of NCA.

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Synthesis of α″-Fe16N2 foils with an ultralow temperature coefficient of coercivity for rare-earth-free magnets

Cited by 27 publications

References 43 publications

Martensitic αʺ-Fe16N2-Type Phase of Non-Stoichiometric Composition: Current Status of Research and Microscopic Statistical-Thermodynamic Model

Martensitic αʺ-Fe16N2-Type Phase of Non-Stoichiometric Composition: Current Status of Research and Microscopic Statistical-Thermodynamic Model

Stable and Monodisperse Iron Nitride Nanoparticle Suspension for Magnetic Diagnosis and Treatment: Development of Synthesis and Surface Functionalization Strategies

Effect of Voltage Range and BiPO₄ Coating on the Electrochemical Properties of LiNi_0.8Co_0.15Al_0.05O₂

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Synthesis of α″-Fe16N2 foils with an ultralow temperature coefficient of coercivity for rare-earth-free magnets

Cited by 27 publications

References 43 publications

Martensitic αʺ-Fe16N2-Type Phase of Non-Stoichiometric Composition: Current Status of Research and Microscopic Statistical-Thermodynamic Model

Martensitic αʺ-Fe16N2-Type Phase of Non-Stoichiometric Composition: Current Status of Research and Microscopic Statistical-Thermodynamic Model

Stable and Monodisperse Iron Nitride Nanoparticle Suspension for Magnetic Diagnosis and Treatment: Development of Synthesis and Surface Functionalization Strategies

Effect of Voltage Range and BiPO4 Coating on the Electrochemical Properties of LiNi0.8Co0.15Al0.05O2

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Effect of Voltage Range and BiPO₄ Coating on the Electrochemical Properties of LiNi_0.8Co_0.15Al_0.05O₂