UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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2022-07-01 17:02

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Conference: Bucharest University Faculty of Physics 2019 Meeting


Section: Solid State Physics and Materials Science


Title:
Interplay of magneto-strictive and magneto-transport properties of Fe-Dy ribbons


Authors:
Claudiu LOCOVEI (1,2), Anda Elena STANCIU (1), Gabriel SCHINTEIE (1), Nicusor IACOB (1), Aurel LECA (1), Mihaela SOFRONIE (1), Victor KUNCSER (1)


Affiliation:
1) National Institute for Materials Physics, P.O.Box MG-7, 077125, Bucharest-Magurele, Romania

2) Bucharest University, Faculty of Physics, 077125, Bucharest-Magurele, Romania


E-mail
anda.stanciu@infim.ro


Keywords:
non-collinear spin structure, magnetic anisotropy, unusual magneto-transport features, rare earth – transition metals alloys


Abstract:
Magnetic interactions and their influence on the magneto-transport and magneto- strictive properties of Fe-Dy amorphous systems with non-collinear magnetic structure were investigated. Interesting magneto-functionalities of such Fe-Dy alloys of interest for applications in spintronics and magneto-optical recording are envisaged. Fe-Dy ribbons of different compositions were prepared by induction melting of the elements followed by ultra-fast quenching on a drum armature. The formation of the amorphous phase was probed via X-Ray Diffraction (XRD) and Mossbauer spectroscopy. The specific spin structure of such sperimagnetic systems was completely resolved (over both Fe and Dy magnetic sublattices) by corroborating in field Transmission Mossbauer Spectroscopy (TMS) and magnetometry data. Considering that the observed spins reorientation under temperature variation is equivalent to a reorientation of the magnetic moments under a tensile stress, a reach information on magneto-strictive effects was inferred from TMS data providing the average angle between the mean direction of the hyperfine magnetic field and the ribbon plane, as collected at different temperatures. Both positive and negative magneto-striction coefficients were evidenced, depending on the Dy content and temperature. Moreover, the observed atypical magneto-resistance curves were interpreted as due to the electron scattering mechanism on the non-collinear spin structure and to an additional contribution related to size variations by reorientation of the magnetic moments under an applied magnetic field specific to such magneto-strictive materials.


Acknowledgement:
This work was supported by the Romanian Ministry of Research via the Core Program PN21N, PN-III-P1-1.2-PCCDI-2017-0871 and POC P_37_697 REBMAT (contract 28/01.09.2016).