Future Trends in Microelectronics: From Nanophotonics to Sensors to Energy

Spin Screening of Magnetization Due to Inverse Proximity Effect in Superconducting/Ferromagnetic Bilayers

V. Shelukhin, M. Karpovski, A. Palevski

School of Physics and Astronomy, Tel Aviv University Tel Aviv 69978, Israel

J. Xia, A. Kapitulnik

Department of Physics, Stanford University Stanford, California 94305, U.S.A.

A. Tsukernik

The Center for Nanoscience and Nanotechnology, Tel Aviv University Tel Aviv 69978, Israel

1.   Introduction

When ferromagnetic (F) films are deposited on top of superconductors (S) they acquire certain superconducting properties. This is the well-known proximity effect which gives rise to a number of spectacular phenomena:^1,2 superconducting critical current oscillations as a function of ferromagnet thickness, long range triplet superconductivity, etc. These effects have been already observed experimentally.^3-5 However, the inverse proximity effect,^6,7 wherein the superconductor inherits ferromagnetic properties, is a subject that so far has not attracted as much experimental attention. Here, we present the transport and optical studies of the inverse proximity effect in superconductor ferromagnetic bilayers. We have measured the magneto-resistance of an array of e-beam lithographically patterned 200 nm thick Pb discs with diameters in the range of 2–5 μm, deposited on top of a 5 nm Ni film. Magneto-optical measurements of the polar Kerr effect using a zero-area-loop Sagnac magnetometer on Pb/Ni and Al/(Co-Pd) proximity-effect bilayers show unambiguous ...