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001-es BibID:	BIBFORM086707
035-os BibID:	(WoS)000546857500001 (Scopus)85087175252
Első szerző:	Kruhlov, Ivan O.
Cím:	Structural phase transformations in annealed Pt/Mn/Fe trilayers / I. O. Kruhlov, O. V. Shamis, N. Y. Schmidt, M. V. Karpets, S. Gulyas, E. Hadjixenophontos, A. P. Burmak, S. I. Sidorenko, G. L. Katona, G. Schmitz, M. Albrecht, I. A. Vladymyrskyi
Dátum:	2020
ISSN:	0953-8984 1361-648X
Megjegyzések:	Thermally-activated phase transitions in Pt/Mn/Fe thin films were investigated by a combination of x-ray diffraction, transmission electron microscopy, secondary neutral mass spectrometry depth profiling, atomic force microscopy, and magnetic properties measurements. Post-annealing was carried out in vacuum to different temperatures up to 620 degrees C. Initially, at temperatures between 280 degrees C-450 degrees C first L1(0)-MnPt is formed at the Mn/Pt interface followed by the most likely formation of metastable bcc Fe3Pt, which gets transformed by further annealing to fcc Fe3Pt and eventually to chemically ordered L1(2)-Fe3Pt. The final product after annealing at 620 degrees C consists of two interesting phases, which are relevant for spintronic applications, antiferromagnetic L1(0)-MnPt with addition of Fe and ferromagnetic L1(2)-Fe3Pt, consistent with the initial element composition.
Tárgyszavak:	Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk chemical ordering solid state reactions magnetic thin films Ll0-mnpt
Megjelenés:	Journal Of Physics-Condensed Matter. - 32 : 36 (2020), p. 1-9. -
További szerzők:	Shamis, O. V. (fizikus) Schmidt, N. Y. Karpets, M. V. Gulyás Szilvia (1993-) (fizikus) Hadjixenophontos, E. Burmak, A. P. Sidorenko, Sergey I. Katona Gábor (1977-) (fizikus) Schmitz, Guido Albrecht, Manfred Vladymyrskyi, Igor A.
Pályázati támogatás:	GINOP-2.3.2-15-2016-00041 GINOP
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM086609
035-os BibID:	(WoS)000561800700005 (Scopus)85086412534
Első szerző:	Kruhlov, Ivan O.
Cím:	Thermally-induced phase transitions in Pt/Tb/Fe trilayers / I. O. Kruhlov, O. V. Shamis, N. Y. Schmidt, S. Gulyas, R. Lawitzki, A. P. Burmak, S. I. Konorev, G. L. Katona, G. Schmitz, M. Albrecht, I. A. Vladymyrskyi
Dátum:	2020
ISSN:	0040-6090
Megjegyzések:	Structural phase formation induced by thermally-activated diffusion processes and intermixing of layered structures is a promising reaction pathway for the synthesis of unexpected (metastable) thin film materials. Furthermore, the sequence of structural phase transitions during annealing can substantially differ from those predicted by corresponding bulk phase diagrams due to the underlying grain boundary diffusion mechanisms as well as surface and interface effects. In this study, phase transitions in Pt/Tb/Fe trilayers occurring during post-annealing up to 620 degrees C were investigated by various techniques including x-ray diffraction, transmission electron microscopy, secondary neutral mass spectrometry, Auger electron spectroscopy depth profiling, and magnetic properties measurements. At an annealing temperature of 215 degrees C pronounced Pt and Tb diffusion intermixing is observed leading to the formation of the binary Pt2Tb phase. Further annealing up to 280 degrees C is accompanied by the appearance of the chemically disordered A1-FePt phase and significant Tb segregation to the outer surface forming an oxide layer. The chemically ordered L(1)0-FePt phase starts to form in parallel to the disappearance of the Pt2Tb phase at 450 degrees C. The final phase product at 620 degrees C is characterized by the coexistence of two remaining phases, L(1)0-FePt and TbO2. Structural phase transitions have a significant impact on the films magnetic properties - heat treatment leads to an enhancement of the coercive field. This fact is associated with the formation of the hard magnetic L(1)0-FePt phase, which might be accompanied by grain isolation induced by partially Tb/Tb-O grain boundary filling.
Tárgyszavak:	Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk diffusion intermixing solid state reactions magnetic thin films terbium l10-ordered iron-platínum
Megjelenés:	Thin Solid Films. - 709 (2020), p. 1-7. -
További szerzők:	Shamis, O. V. (fizikus) Schmidt, N. Y. Gulyás Szilvia (1993-) (fizikus) Lawitzki, R. Burmak, A. P. Konorev, S. I. Katona Gábor (1977-) (fizikus) Schmitz, Guido Albrecht, Manfred Vladymyrskyi, Igor A.
Pályázati támogatás:	GINOP-2.3.2-15-2016-00041 GINOP
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM103238
035-os BibID:	(WOS)000570817200001 (Scopus)85091078768
Első szerző:	Makushko, P. V.
Cím:	Formation of ordered L10-FePt phase in FePt-Ag thin films / P. V. Makushko, M. N. Shamis, N. Y. Schmidt, I. E. Kotenko, S. Gulyas, G. L. Katona, T. I. Verbytska, D. L. Beke, M. Albrecht, Iu. M. Makogon
Dátum:	2020
ISSN:	2190-5509 2190-5517
Megjegyzések:	In this work, the influence of an Ag layer, which is located at different positions of the layer stack (top, intermediate, bottom), on the structural and magnetic properties of orderedL1(0)phase in Fe(50)Pt(50)films was investigated. It was found that the position of an additional Ag layer affects the stress state of the as-deposited FePt films. Mechanical stress is induced during deposition and post-annealing process due to the difference in thermal expansion coefficients and lattice mismatch of FePt, Ag, and substrate. The initial stress state affects the ordering process during subsequent heat treatment. The higher level of initial compressive stress (- 7.8 GPa) in FePt/Ag/FePt films results inL1(0)phase formation at a temperature of 700 degrees C which is about 100 degrees C lower than in films with Ag bottom (- 3.6 GPa) and top (+ 0.86 GPa) layers. A more pronounced (001) oriented growth of theL1(0)phase was observed in stacks with Ag top layer as compared to Ag bottom and intermediate layers. The highest values of coercivity were obtained for films with Ag intermediate and bottom layers, which is due to the distribution of Ag along FePt grain boundaries that result in strong exchange decoupling of FePt grains. Furthermore, the formation of the orderedL1(0)phase at comparatively low temperatures of about 370 degrees C was observed in a free-standing FePt/Ag (30 nm)/FePt film.
Tárgyszavak:	Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk Stress state Annealing Ordering L1(0)-FePt phase Coercivity
Megjelenés:	Applied Nanoscience. - 10 : 12 (2020), p. 4809-4816. -
További szerzők:	Shamis, M. N. Schmidt, N. Y. Kotenko, I. E. Gulyás Szilvia (1993-) (fizikus) Katona Gábor (1977-) (fizikus) Verbytska, T. I. Beke Dezső László (1945-) (fizikus) Albrecht, Manfred Makogon, I. M.
Pályázati támogatás:	V4EaP Scholar-ship 51300654 Egyéb GINOP-2.3.2-15-2016-00041 GINOP
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM079100
035-os BibID:	(WoS)000466269900001 (Scopus)85065808233
Első szerző:	Shamis, O. V. (fizikus)
Cím:	Phase transformations in Pt/Fe bilayers during post annealing probed by resistometry / O. V. Shamis, N. Y. Safonova, M. M. Voron, A. P. Burmak, S. I. Sidorenko, G. L. Katona, S. Gulyas, D. L. Beke, M. Albrecht, I. A. Vladymyrskyi
Dátum:	2019
ISSN:	0953-8984 1361-648X
Megjegyzések:	X-ray diffraction (XRD), secondary neutral mass spectrometry (SNMS) depth profiling, and electrical resistivity measurements were used to follow the phase transformations in Pt/Fe bi-layered thin films during annealing. Initially, the electrical resistivity increases linearly with temperature up to 150 °C due to the contribution of phonon scattering of the metallic Pt and Fe bilayer. Further increase of the annealing temperature leads to a steeper linear increase, which is associated with the initial formation of the chemically disordered A1-phase followed by the formation of the chemically ordered L10-FePt phase, as confirmed by XRD and SNMS studies. Finally, at about 620 °C the single L10-FePt phase has formed throughout the film. Moreover, the electrical resistivity contains also the magnetic contribution to the total resistivity. In this case, the loss in magnetic order is indicated by a change in temperature dependence of the resistivity at about 310 °C, representing the Curie temperature of the initially formed A1-FePt alloy, while the finally formed L10-FePt alloy reveals a higher magnetic transition temperature of about 410 °C. In this study, it has been demonstrated that resistometry in combination with structural and chemical analysis provides valuable information on diffusion processes, structural phase formations and its stability range, as well as on the magnetic transition temperature.
Tárgyszavak:	Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk electrical resistivity chemical ordering magnetic thin films FePt
Megjelenés:	Journal Of Physics-Condensed Matter. - 31 : 28 (2019), p. 1-7. -
További szerzők:	Safonova, N. Y. Voron, M. M. Burmak, A. P. Sidorenko, Sergey I. Katona Gábor (1977-) (fizikus) Gulyás Szilvia (1993-) (fizikus) Beke Dezső László (1945-) (fizikus) Albrecht, Manfred Vladymyrskyi, Igor A.
Pályázati támogatás:	GINOP-2.3.2-15-2016-00041 GINOP
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
Borító:
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