The nanocrystalline powders offer opportunities for the design of soft magnetic materials with improved magnetic properties (high saturation magnetization, high permeability, low magnetostriction) to be used for high frequency applications magnetic cores [1-4]. The aim of the work is to develop Fe73.5Cu1Nb3Si13.5B9 powders with a high percentage of particles having the size in the range where nanocrystalline state is directly achieved, by using a new three-jet gas atomization technique (consisting in the use two jets of Ar gas and one jet of water), directed in such a configuration so that the molten alloy jet to be successively fragmented in droplets by the gas jets and further broken intro droplets and cooled by the liquid jet. Powders with the diameter size in the ranges 0-20 µm, 20-32 µm, 32-63 µm, and 63-100 µm have been prepared. Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), thermomagnetic, and magnetic measurements have been performed to assess the structural and magnetic differences of powders between the groups of samples after sieving. The SEM images revealed the formation of particles with almost spherical shape. The X-Ray diffraction patterns show that in the range 0-32 µm the structure of particles is a mixture of amorphous and nanocrystalline phases, approx. 50 % of particles being in amorphous state, which is a quite high percentage. The magnetic measurements, performed using the Vibrating Sample Magnetometer technique (VSM) show that the Curie temperature increases from 350°C to 520°C and the saturation magnetization is between 130 to 145 emu/g. The coercive field, Hc, takes a very low value of 4 Oe for as-cast powders with the smallest diameter range, the value decreasing to down to under 2 Oe after annealing. These properties combined with good thermal stability, low cost price, the possibility to develop components with reduced dimensions/masses, make the amorphous and nanocrystalline alloys competitive and economic solutions in electronics, telecommunications, sensors, etc.
Work supported by the Romanian Ministry of Research, Innovation and Digitalization under NUCLEU Program – contract no. 33N/2019, project PN 19 28 01 01. 
**References:** [1] T. Suzuki, P. Sharma, and L. Jiang, IEEE Trans. Magn., Vol. 54, 2801705 (2018) 
[2] L. Chang, L. Xie, and M. Liu, J. Magn. Magn. Mater., Vol. 452, p. 442 (2018) 
[3] K.L. Alvarez, J.M. Martín, and M. Ipatov, J. Alloys Compd., Vol. 735, p. 2646 (2018) 
[4] K. L. Alvarez, H.A. Baghbaderani, and J.M. Martín, J. Magn. Magn. Mater., Vol. 501, 166457, (2020)

Synthesis of Amorphous and Nanocrystalline Powders by a Three Jet Gas Liquid Technique

Fe-Nb-Cr-B rapidly quenched melt-spun ribbons (MSRs) show glassy structures in the as-quenched state and Curie temperatures (TC) of 290-330 K depending on the Cr content [1]. The medical applications are usually requiring submicron powders, which can be easily targeted to the sick body organs by means of the external magnetic field [2]. The present work focusses on the preparation of Fe67.2Nb0.3Cr12.5B20 submicron powders by high-energy ball milling from MSRs precursors, using different milling agents: oleic acid (OA), sodium oleate (NAOL) and stearic acid (SA). The main challenge is to preserve the glassy structure from MSRs through the milling process, because only the glassy structure guarantees the low TC. MSRs were annealed at 4000C for 1 h to facilitate the milling. The ratio stainless steel balls:powder was of 50:1. The powders milled in OA and NAOL in the ratio of 1:1 have been washed in n-heptane and dried at 700C in vacuum, while for the ones milled in SA, in the ratio of 5:1, trichloroethylene was used for removing the surfactant. After 150 h of milling in OA the powders have ~100 nm, XRD and UHR-TEM investigations indicating the presence of only the glassy structure and the absence of precipitating crystalline phases. The milling up to 250 h reduces the size of the powders to &lt; 50 nm, while the glassy structure is preserved, as confirmed also by the same TC value (~450C) as for the precursor MSRs. The milling in NAOL keeps the powders in the range of 800÷900 nm, while TC remains ~450C. The milling over 100 h in NAOL results in an increase of TC to 650C and of Ms to 45 Am2/kg, compared with MSRs powders milled in OA (Ms = 35 Am2/kg). The increase of TC and Ms is even more obvious for the powders milled in SA (1100C and 112 Am2/kg, respectively). Moreover, the powders milled in SA are not changing their size even after 50 h of milling, i.e. ~5 µm, comparable with the ones of the precursor MSRs. However, the HR-SEM images indicate round shaped powders after milling in SA, compared with the starting lamellar pieces of MSRs, while the XRD and SAED patterns emphasize similar glassy structures for powders and MSRs. Financial support by the NUCLEU Program (PN 19 28 01 01) is gratefully acknowledged.

Influence of wet and dry milling conditions on the evolution of microstructure and TC of Fe-Cr-Nb-B glassy powders

The high performance permanent magnets are indispensable for many commercial and military applications. Rare-earth hard magnetic nanoparticles have drawn great attention due to their potential applications in nanocomposite permanent magnets with high performance. Different methods have been employed to prepare hard magnetic nanoparticles including chemical methods, electrodeposition, spark erosion and ball milling. The ball milling technique, used for the preparation of nanoparticles, is a simple, inexpensive and efficient method for size reduction of nanocrystalline powders. The experimental parameters involved in ball-milling technique, such as milling time, milling energy, and ball size, are determinant in what concerns the magnetic properties of the nanoparticles. The milling temperature and milling medium are also known as critical factors impacting the morphology and performance of the nanoparticles. Here, we report results on the morphology, structure, and magnetic properties of Ce14Fe76Co4B6 nanoparticles prepared by high-energy ball milling at low temperature, in liquid nitrogen, from nanaocristaline ribbons precursors. At regulate intervals of time, in the milling vial was introduced liquid nitrogen, in order to compensate the evaporation. We found that: (i) the optimal interval for introducing liquid nitrogen into the vial is 20 minutes, since for a longer interval, the liquid nitrogen evaporates and the sample becomes contaminated, (ii) the morphology and size of the powders change with the milling time, from large particles with irregular shapes to small dimensions (about 150 nm) and rounded shapes for a milling time of 420 minutes (the microstructure of powders milled 420 h, is shown in Figure 1.) (iii) the structure and magnetic properties of the nanoparticles were kept close to those of the precursor ribbons by milling in liquid nitrogen (a comparison between the hysteresis curves for powders and the precursor ribbons is shown in Figure 2). The Ce14Fe76Co4B6 nanoparticles obtained by ball milling in liquid nitrogen have great potential to be used for the production high performance nanocomposite permanent magnets. Acknowledgement This work was supported by a grant of the Romanian Ministry of Education and Research, CCCDI - UEFISCDI, project number PN-III-P2-2.1-PED-2019-2054, within PNCDI III. &lt;!--![endif]----&gt;&lt;!--![endif]----&gt;&lt;!--![endif]----&gt;

**References:**

[1] Baolu Zhou, Zhongxue Li and Congcong Chen, Global Potential of Rare Earth Resources and Rare Earth Demand from Clean Technologies, Minerals 7 (2017) 203. [2] Thanh Anh Huynh and Min-Fu Hsieh, Performance Analysis of Permanent Magnet Motors for Electric Vehicles (EV) Traction Considering Driving Cycles, Energies 11 (2018) 1385. [3] M. Grigoras, M. Lostun, G. Stoian, D.D. Herea, H. Chiriac, N. Lupu, Microstructure and magnetic properties of Ce10+xFe84−xB6 nanocrystalline ribbons versus preparation conditions, J. Magn. Magn. Mater. 432 (2017) 119–123. [4] J. F. Herbst, M. S. Meyer and F. E. Pinkerton, Magnetic hardening of Ce2Fe14B, J. Appl. Phys. 111, 07A718 (2012).

**Images:**

![](https://assets.underline.io/uploads/markdown_image/1/image/eaaa31845ba980e59e6fd93570814151.jpg)
Fig 1. The SEM micrograph of Ce14Fe76Co4B6 
powders milled 420 h in liquid nitrogen.

![](https://assets.underline.io/uploads/markdown_image/1/image/c84ddc682ad13f3ca51fdaac70d5be13.jpg)
Fig 2. The hysteresis curve of Ce14Fe76Co4B6 ribbons (black) and powders (red) milled 420 h in liquid nitrogen.

 Characterization and Magnetic properties of Ce-FeCo-B Nanoparticles Prepared by Cryo-milling

**Please click on the poster to see the abstract or leave your comment to the author.** 
**Session Chair:** Cristina Bran, *Instituto de Ciencia de Materiales de Madrid*

JPA: Amorphous and Nanocrystalline Soft Magnets II

poster

#### Welcome to the 67th Annual Conference on Magnetism and Magnetic Materials, MMM 2022!

The Conference was held from October 31 to November 4 and offers both in-person and on-demand content.

MMM 2022 is sponsored jointly by AIP Publishing and the IEEE Magnetics Society. Members of the international scientific and engineering communities interested in recent developments in fundamental and applied magnetism are invited to attend and contribute to the technical sessions. The technical program will include invited and contributed papers in oral and poster sessions, invited symposia, a tutorial, and several special sessions. This Conference provides an outstanding opportunity for worldwide participants to meet their colleagues and collaborators and discuss developments in all areas of magnetism research.

<iframe width="560" height="315" src="https://s3.amazonaws.com/pf-user-files-01/u-59356/uploads/2022-11-02/un13zp7/MMM%20Welcome%20Video%20v5.mp4" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

For tickets to the event, please register at the following link: https://magnetism.org/registration

Please register for the MMM 2022 conference to join the event.

MMM 2022

This Conference provides an outstanding opportunity for worldwide participants to meet their colleagues and collaborators and discuss developments in all areas of magnetism research.

**Session chair:** Ahmed Talaat, University of Pittsburgh



COA - Soft Magnetic Materials I: Amorphous and Nanocrystalline

technical paper

The 15th Joint MMM-INTERMAG Conference (2022 Joint) is sponsored jointly by AIP Publishing and the IEEE Magnetics Society. Members of the international scientific and engineering communities interested in recent developments in fundamental and applied magnetism are invited to attend and contribute to the technical sessions. The technical program will include invited and contributed papers in oral and poster sessions, invited symposia, a plenary session, and an evening session, with about 1500 presentations overall. This Conference provides an outstanding opportunity for worldwide participants to meet their colleagues and collaborators and discuss developments in all areas of magnetism research.

The 2022 Joint Conference will offer both in-person and prerecorded on-demand content.

For tickets to the event, please register at the following link: https://magnetism.org/register

Please register for the Joint MMM-Intermag conference to join the event.

2022 Joint MMM-INTERMAG

*Session Co-Chair: Alberto Bollero, IMDEA Nanoscience*

*Session Co-Chair: Kinjal Gandha, Iowa State University*

These on-demand presentations are available to view at your leisure.

JW: RE-based and RE-free Permanent Magnets

INTERMAG 2021 Welcome Video



	
<figure class="video_container">
 <iframe src="https://screencast-o-matic.com/player/crflqFVnUpZ?v=6&ff=1&title=0&controls=1" width=640 height=360 frameborder="0" allowfullscreen="true"> </iframe>
</figure>

Want to buy a ticket? 

Register for INTERMAG 2021 here

[![](https://assets.underline.io/uploads/markdown_image/1/image/17ce76e7960db633258024eef8d6da7f.png)](https://intermag.org/register)

Got your ticket, but still can’t access the event?

Contact us and our team will look into it.

Marian Grigoras

3

SHORT BIO

Presentations

Synthesis of Amorphous and Nanocrystalline Powders by a Three Jet Gas Liquid Technique

Influence of wet and dry milling conditions on the evolution of microstructure and TC of Fe-Cr-Nb-B glassy powders

Characterization and Magnetic properties of Ce-FeCo-B Nanoparticles Prepared by Cryo-milling

Stay up to date with the latest Underline news!

PRESENTATIONS

CONFERENCES

COMPANY

RESOURCES