We report second-harmonic magneto-optic Kerr measurements on air-exposed, polycrystalline Ni81Fe19 thin films, ranging in thickness from 1 nm to 2 μm, on Al2O3 coated Si (001). For samples thicker than 20 nm, in the transverse Kerr geometry, we observe a factor of 4 change in second-harmonic intensity upon magnetization reversal. For thin samples, we observe interference between second-harmonic fields from the various interfaces and deterioration of ferromagnetism in the 1 and 2 nm films. Modeling suggests that the Ni81Fe19/Al2O3 interface has a larger second-order susceptibility than the air/Ni81Fe19 surface.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)