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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 1:36 |
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Conference: Bucharest University Faculty of Physics 2021 Meeting
Section: Solid State Physics and Materials Science
Title:
AuxFe1-x nanophasic thin films with novel features
Authors:
Claudiu LOCOVEI(1,2), Anda STANCIU(1), Cristian RADU (1,2), Simona GRECULEASA(1), Gabriel SCHINTEIE(1), Petru PALADE(1), Andrei KUNCSER(1), Nicusor IACOB(1), Aurel LECA(1), Andrei ALEXANDRU-DINU(1,2), Victor KUNCSER(1)
*
Affiliation:
1) National Institute of Materials Physics, 077125 Magurele, Romania
2) University of Bucharest, Faculty of Physics, 077125 Magurele, Romania
E-mail
claudiu.locovei@infim.ro
Keywords:
nanophasic system, thin films, Fe clusters self-assembling, uniaxial magnetic anisotropy, hcp Au structure
Abstract:
Nanoscale materials with novel properties have been found their place in a tremendous widely network of applications. Among them, multifunctional nanocomposite thin films present a very high interest due to the possible simple preparation and versatile engineering of their properties. In this reason, AuxFe1-x nanophasic thin films with different thicknesses were deposited by RF magnetron sputtering, and, subsequently, their morpho-structural, magnetic, and magneto-transport characterization has been performed. The results show that for a narrow interval of thickness and elemental ratios, Fe clusters self-assembles into lamellar forms embedded in the gold matrix. Also, the data collected at MOKE reveal the in-plane uniaxial magnetic anisotropy in case of the lamellar 2D organization of the magnetic clusters and no in plane magnetic texture of the same randomly distributed clusters. SQUID magnetometry performed in two geometries (with the field in the film plane and perpendicular to it, respectively) and at different temperatures confirm the strong in-plane magnetic texture for a series of samples with critical composition and thickness and a magnetic domain structure without magnetic texture in case of samples with a higher amount of Fe. The spectra acquired by Conversion Electron Mossbauer Spectroscopy were fitted with a hyperfine magnetic field distribution corresponding to distorted Fe configurations with Au impurities for the AuxFe1-x nanophasic systems of intermediate Fe content (30% at.) and with central superparamagnetic components in case of samples with lower Fe content. XRD and SAED analysis highlight the formation of hexagonal close-packed Au in the samples where is evidenced the uniaxial magnetic anisotropy together with lamellar formation of Fe clusters. Magneto-resistive (MR) data were recorded at various temperatures and with magnetic field orientated parallel, and respectively perpendicular to the substrate plane. MR curves show specific magneto-resistance effects related to the type of self-organization of the magnetic clusters and to the crystalline structure of the Au matrix.
Acknowledgement:
This research was funded by the Core Program PN030101-nr.21N/2019 and EIT through Project 17167-RAISESEE.
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