Anomalous Switching of Nb/Ni Ferromagnetic/Superconducting Multilayers
Abstract
[Nbx/Niy]5 multilayers (ML), with x = 10 and 23 nm, and y = 2.5, 3.5 and 5.0 nm, were grown by dc magnetron sputtering on (100) Si substrates. The field and temperature dependences of the magnetic moment were investigated with dc magnetic field applied in the ML plane. The x = 23 nm samples exhibited complex magnetic hysteresis that reflects a strong interplay between Meissner currents, flux trapped in the Nb layers, and the Ni layer magnetization. Smooth ferromagnetic hysteresis was observed in normal state magnetization curves. In contrast, the superconducting state magnetization curves exhibited abrupt, reproducible switching anomalies for thick Ni layers, whereas, samples with thinner Ni layers exhibit random jumps in the magnetization curves, which we conclude are a very sensitive probe of the ferromagnetic stability of the Ni layers.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARN23014K