Superconductivity and magnetic properties of Fe/Nb multilayers (abstract)

Journal Article · Mon Apr 01 00:00:00 EST 1996 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.362042· OSTI ID:282095

Muehge, T; Zoller, I; Westerholt, K; Zabel, H ^[1]; Goryunov, Y V; Garifyanov, N N; Khaliullin, G G; Garifullin, I A ^[2]; Tagirov, L R ^[3]

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1. Institut fuer Experimentalphysik/Festkoerperphysik, Ruhr-Universitaet Bochum, 44780 Bochum (Germany)
2. Kazan Physical--Technical Institute of Russian Academy of Sciences, 420029 Kazan (Russian Federation)
3. Kazan State University, 420008 Kazan (Russian Federation)

Interplay between superconductivity (SC) and ferromagnetism (FM) in dilute magnetic alloys and intermetallic compounds attracted considerable attention during the last 30 years. Usually the FM state is more stable and therefore tends to suppress SC. On the other hand, the magnetic state can be changed due to a modification of the RKKY interaction in the SC state. Mutual influence of SC and FM may acquire new peculiarities in such artificial systems as FM/SC multilayers. This work is focused on the study of Fe/Nb multilayered system, prepared on Al{sub 2}O{sub 3}(11{bar 2}0) substrates by rf-sputtering and by molecular beam epitaxy (MBE) techniques. The Nb thickness {ital t}{sub Nb} was varied from 150 to 500 A and the Fe thickness {ital t}{sub Fe} was changed from 5 to 100 A. The sputtered samples were highly layered with sharp interfaces as revealed by x-ray reflectivity and were textured in the [110] direction. The epitaxial MBE samples showed (110) growth of Nb and Fe with a coherence lengths comprising the total film thickness. Surface and interface roughnesses were very small. The dependence of the ferromagnetic resonance (FMR) spectra parameters on the direction of the dc magnetic field rotating in the plane of the samples show sixfold anisotropic behavior indicating the well known three-domain in-plane structure of Fe layers on sapphire substrates. FMR and SQUID measurements showed that FM of Fe layers survived down to {ital t}{sub Fe}=10 A. The out-of-plane FMR measurements also showed that the easy axis of magnetization lies in the plane of the samples down to this thickness. The superconducting transition temperature {ital T}{sub {ital c}} was determined by measurements of the electrical resistivity and by SQUID measurements. It was established that there is a critical thickness of the Fe layer {ital t}{sub Fe}{sup crit} above which SC was not detected for temperatures down to 1.5 K. This value was dependent on {ital t}{sub Nb}. (Abstract Truncated)

• OSTI ID: 282095
• Report Number(s): CONF-951101-; ISSN 0021-8979; TRN: 96:023732
• Journal Information: Journal of Applied Physics, Vol. 79, Issue 8; Conference: 40. conference on magnetism and magnetic materials, Philadelphia, PA (United States), 6-9 Nov 1995; Other Information: PBD: Apr 1996
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
IRON
MAGNETIC PROPERTIES
NIOBIUM
SUPERCONDUCTIVITY
LAYERS
MOLECULAR BEAM EPITAXY
FERROMAGNETIC RESONANCE
DOMAIN STRUCTURE
THICKNESS
TRANSITION TEMPERATURE
TEMPERATURE RANGE 0000-0013 K
MULTILAYERS
SPUTTERED MATERIALS