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In Honor of Nobel Laureate Dr. Avram Hershko
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SIPS 2024 takes place from October 20 - 24, 2024 at the Out of the Blue Resort in Crete, Greece

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More than 500 abstracts submitted from over 50 countries


Featuring many Nobel Laureates and other Distinguished Guests

ADVANCED PROGRAM

Orals | Summit Plenaries | Round Tables | Posters | Authors Index


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Oral Presentations


SESSION:
SISAMTuePM2-R6
Schultz International Symposium (8th Intl. Symp. on Science of Intelligent & Sustainable Advanced Ferromagnetic and Superconducting Magnets (SISAM))
Tue. 22 Oct. 2024 / Room: Knossos
Session Chairs: Hans Fecht; Student Monitors: TBA

15:05: [SISAMTuePM207] OS Invited
MARKET AND APPLICATIONS OF RARE-EARTHS: THE RELEVANCE OF RARE-EARTH PERMANENT MAGNETS
Marcos De Campos1; Amilton Da Silva Jr2; Kaio St De Souza1; Ingrid R De Lima1; Jose Adilson De Castro1
1Federal Fluminense University, Volta Redonda, Brazil; 2CEFET - RJ, Valença , Brazil
Paper ID: 287 [Abstract]

The present situation of the market and applications of rare-earths is reviewed. It is given special attention for discussing the possibility of substitution of  rare-earth magnets by other families of magnets.

Three are the main commercial applications of rare-earths: i) luminescent phosphors, ii) magnets, and iii) catalysis.

For catalysis, the cheap rare-earths as cerium and lanthanum are employed.  Luminescent phosphors are essential in many applications, as lasers and, for example, erbium is used in optical fibers. However, in spite of its relevance, erbium is not expensive as Tb and Dy. 

In LED applications, the rare-earths are used as thin films, and , thus the demand in volume  is not very significant when compared with the demand for magnets. The use of white LED (light emission diode) significantly reduced the demand for europium after 2015, but this application is still relevant. In the 1960s and up the 1980s, Europium was the most expensive rare-earth, due to extreme demand.

The rare-earth market is nowadays driven by Tb, Dy, Nd and Pr, which are employed in rare-earth iron permanent magnets of the RE2Fe14B family (RE=rare earth). For applications in high temperature, dysprosium and terbium are added, and this made the demand and price of Dy and Tb be skyrocketing.

SmCo magnets have the problem of using the expensive element cobalt. Nowadays the demand and price of cobalt increased conbseiderably due to application in rechargeable battteries, and thus, SmCo use in large scale is avoided, but they remain relevant for high temperature applications (above 150oC).

Possible alternatives for rare-earth  permanents magnets are discussed. Among the few options for replacement are the ferrite magnets (BaFe12O19 or SrFe12O19), the Alnico magnes based on shape anisotropy and maybe iron nitrogen. Economic and technical feasibility of these families of magnets are discussed.

Its is given a brief overview about recent mining projects in Brazil, which are focusing on ionic clays, with the objective of extracting the scarce and expensive elements terbium and dysprosium. 



15:45 COFFEE BREAK/POSTERS/EXHIBITION - Ballroom Foyer

SESSION:
SISAMTuePM4-R6
Schultz International Symposium (8th Intl. Symp. on Science of Intelligent & Sustainable Advanced Ferromagnetic and Superconducting Magnets (SISAM))
Tue. 22 Oct. 2024 / Room: Knossos
Session Chairs: Carlo Burkhardt; Student Monitors: TBA

18:10: [SISAMTuePM415] OS
DETERMINATION OF MAGNETIC ANISOTROPY IN ALNICO, COBALT-NEEDLES AND SmFeN
Marcos De Campos1; Fernanda A Sampaio Da Silva1; Kaio St De Souza1; Charle Correia Da Silva2; Ingrid R De Lima1; Jose Adilson De Castro1
1Federal Fluminense University, Volta Redonda, Brazil; 2UFF, Volta Redonda , Brazil
Paper ID: 517 [Abstract]

It was recently presented a model [1-3] able to predict the magnetic anisotropy of any sample, This is called the "Simultanoeus Fitting Method" SFM.

According the SFM method, the magnetic anisotropy can be determined, since magnetic measurements are performed at the  (_|_) perpendicular and (//) parallel directions (relative to the alignment direction). The method assumes samples with alignment in one preferential direction, thus with uniaxial anisotropy. This kind of anisotropy is typically found in samples prepared by powder metallurgy, where the alignbment is obtained by applying magnetic fields in grains with single domain size. 

Using the SFM, the crystallographic texture of samples can be determined directly from magnetic measurements, avoiding complicated, laborious and expensive techniques as EBSD - Electron BackSacterred Diffraction.

A symmetrical distribution as for example the Gaussian, is used for describing the crystallographic texture.

Other distribution functions can also be used, since they are symmetrical. This includes Cauchy -Lorentz, Voigt and Pearson VII as possibilities.

It is experimentally found that f=cos(theta)^n or Gaussian distributions describe very well the texture of the samples.

The model allows the re-evaluation of experimental data. Here it is discussed how to apply the model in very different samples.

These samples are SmFeN (magnetocrystalline anisotropy), Alnico, (shape anisotropy [4,5]) and cobalt-needle samples.

In cobalt needle samples the shape anisotropy and the magnetocrystalline anisotropy may have the same order of magnitude.

It is discussed the question of dominant anisotropy.

References:
[1] https://link.springer.com/article/10.1007/s11837-024-06586-3
[2] https://ieeexplore.ieee.org/abstract/document/10297507
[3] https://www.sciencedirect.com/science/article/abs/pii/S0304885322010046
[4] https://www.bunting-berkhamsted.com/bunting-supports-brazilian-university-understand-shape-anisotropy-and-magnetic-texture/
[5] https://www.scientific.net/MSF.869.591


18:50 GALA DINNER/AWARDS CEREMONY/SHOW - Marika A Ballroom