Boosting the superconducting spin valve effect in a metallic superconductor/ferromagnet heterostructure  

作　　者：Pavel V. Leksin Andrey A. Kamashev Joachim Schumann Vladislav E. Kataev Jurgen Thomas Bernd Buchner Ilgiz A. Garifullin 

机构地区：[1]Leibniz Institute for Solid State and Materials Research Dresden (IFW Dresden), DoO 1171 Dresden, Germany [2]Zavoisky Physical-Technical Institute, Russian Academy of Sciences, 420029 Kazan, Russia [3]Dresden University of Technology, D-01062 Dresden, Germany

出　　处：《Nano Research》2016年第4期1005-1011,共7页纳米研究（英文版）

摘　　要：Superconducting spin valves based on the superconductor/ferromagnet （S/F） proximity effect are considered to be a key element in the emerging field of superconducting spintronics. Here, we demonstrate the crucial role of the morphology of the superconducting layer in the operation of a multilayer S/F1/F2 spin valve. We study two types of superconducting spin valve heterostructures, with rough and with smooth superconducting layers, using transmission electron microscopy in combination with transport and magnetic characterization. We find that the quality of the S/F interface is not critical for the S/F proximity effect, as regards the suppression of the critical temperature of the S layer. However, it appears to be of paramount importance in the performance of the S/F1/F2 spin valve. As the morphology of the S layer changes from the form of overlapping islands to a smooth case, the magnitude of the conventional superconducting spin valve effect significantly increases. We attribute this dramatic effect to a homogenization of the Green function of the superconducting condensate over the S/F interface in the S/F1/F2 valve with a smooth surface of the S laver.Superconducting spin valves based on the superconductor/ferromagnet （S/F） proximity effect are considered to be a key element in the emerging field of superconducting spintronics. Here, we demonstrate the crucial role of the morphology of the superconducting layer in the operation of a multilayer S/F1/F2 spin valve. We study two types of superconducting spin valve heterostructures, with rough and with smooth superconducting layers, using transmission electron microscopy in combination with transport and magnetic characterization. We find that the quality of the S/F interface is not critical for the S/F proximity effect, as regards the suppression of the critical temperature of the S layer. However, it appears to be of paramount importance in the performance of the S/F1/F2 spin valve. As the morphology of the S layer changes from the form of overlapping islands to a smooth case, the magnitude of the conventional superconducting spin valve effect significantly increases. We attribute this dramatic effect to a homogenization of the Green function of the superconducting condensate over the S/F interface in the S/F1/F2 valve with a smooth surface of the S laver.

关 键 词：SPINTRONICS superconductivi FERROMAGNETISM proximity effect 

分 类 号：TN389[电子电信—物理电子学] O413[理学—理论物理]