Synthesis, Characterization, and Magnetoresistive Properties of the Epitaxial Pd0.96Fe0.04/VN/Pd0.92Fe0.08 Superconducting Spin-Valve Heterostructure

Nanomaterials

Airat Kiiamov¹  Igor Yanilkin¹  Wael Mohammed¹  Amir Gumarov¹  Roman Yusupov¹  Lenar Tagirov¹ 

[1] Institute of Physics, Kazan Federal University, Kremlyovskaya str. 18, 420008 Kazan, Russia;

关键词: spintronics;    superconducting spin-valve;    epitaxial thin-film heterostructure;    palladium-iron alloy;    vanadium nitride;   

DOI  :  10.3390/nano11010064

来源: DOAJ

【 摘 要 】

A thin-film superconductor(S)/ferromagnet(F) F1/S/F2-type Pd_0.96Fe_0.04(20 nm)/VN(30 nm)/Pd_0.92Fe_0.08(12 nm) heteroepitaxial structure was synthesized on (001)-oriented single-crystal MgO substrate utilizing a combination of the reactive magnetron sputtering and the molecular-beam epitaxy techniques in ultrahigh vacuum conditions. The reference VN film, Pd_0.96Fe_0.04/VN, and VN/Pd_0.92Fe_0.08 bilayers were grown in one run with the target sample. In-situ low-energy electron diffraction and ex-situ X-ray diffraction investigations approved that all the Pd_1−xFe_x and VN layers in the series grew epitaxial in a cube-on-cube mode. Electric resistance measurements demonstrated sharp transitions to the superconducting state with the critical temperature reducing gradually from 7.7 to 5.4 K in the sequence of the VN film, Pd_0.96Fe_0.04/VN, VN/Pd_0.92Fe_0.08, and Pd_0.96Fe_0.04/VN/Pd_0.92Fe_0.08 heterostructures due to the superconductor/ferromagnet proximity effect. Transition width increased in the same sequence from 21 to 40 mK. Magnetoresistance studies of the trilayer Pd_0.96Fe_0.04/VN/Pd_0.92Fe_0.08 sample revealed a superconducting spin-valve effect upon switching between the parallel and antiparallel magnetic configurations, and anomalies associated with the magnetic moment reversals of the ferromagnetic Pd_0.92Fe_0.08 and Pd_0.96Fe_0.04 alloy layers. The moderate critical temperature suppression and manifestations of superconducting spin-valve properties make this kind of material promising for superconducting spintronics applications.

【 授权许可】

Unknown