Denitrogenation process in ThMn12 nitride by in situ neutron powder diffraction

Aubert, A. ; Puente-Orench, I. ; Porro, J.M. ; Luca, S. ; Garitaonandia, J.S. ; Barandiaran, J.M. ; Hadjipanayis, G.C.

Resumen: ThMn12 nitrides are good candidates for high performance permanent magnets. However, one of the remaining challenges is to transfer the good properties of the powder into a useful bulk magnet. Thus, understanding the denitrogenation process of this phase is of key importance. In this study, we investigate the magnetic and structural stability of the (Nd0.75, Pr0.25)1.2Fe10.5Mo1.5Nx compound (x=0 and 0.85) as function of temperature by means of neutron powder diffraction. Thermal dependence of the lattice parameters, formation of a-(Fe, Mo), as well as the nitrogen content in the nitrides are investigated by heating the compounds up to 1010 K. The decomposition takes place mainly via the formation of the a-(Fe, Mo) phase, which starts at around 900 K, whereas the nitrogen remains stable in the lattice. Additionally, we show that the magnetic properties of the nitrides [M(4T)=90 Am2/kg and Hc=0.55 T] are maintained after the thermal treatments up to 900 K. This study demonstrates that the ThMn12 nitrides with the Mo stabilizing element offer good prospects for a bulk magnet provided an adequate processing route is found.

Idioma: Inglés

DOI: 10.1103/PhysRevMaterials.5.014415

Año: 2021

Publicado en: PHYSICAL REVIEW MATERIALS 5, 1 (2021), 014415 [7 pp]
ISSN: 2475-9953

Factor impacto JCR: 3.98 (2021)

Categ. JCR: MATERIALS SCIENCE, MULTIDISCIPLINARY rank: 160 / 345 = 0.464 (2021) - Q2 - T2

Factor impacto CITESCORE: 6.4 - Physics and Astronomy (Q1) - Materials Science (Q1)

Factor impacto SCIMAGO: 1.2 - Physics and Astronomy (miscellaneous) (Q1) - Materials Science (miscellaneous) (Q1)

Financiación: info:eu-repo/grantAgreement/EC/H2020/686056/EU/NOVel, critical materials free, high Anisotropy phases for permanent MAGnets, by design/NOVAMAG

Tipo y forma: Artículo (Versión definitiva)