Eur. Phys. J. Appl. Phys. (2014) 68: 10402
https://doi.org/10.1051/epjap/2014140141

Surface plasmon resonance enhancement of the magneto-optical Kerr effect in Cu/Co/Ag/SnO₂ structure

¹ Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Evin, 1983969411 Tehran, Iran
² Solar Cells Research Group, Shahid Beheshti University, G.C., Evin, 1983969411 Tehran, Iran
³ Institute of Nanoscience and Nanotechnology, University of Kashan, 8731751167 Kashan, Iran

^a e-mail: m.moradi@kashanu.ac.ir

Received: 7 April 2014
Revised: 18 August 2014
Accepted: 8 September 2014
Published online: 10 October 2014

Abstract

In this paper, an Ag ultra thin layer was deposited on the Cu/Co film by thermal evaporation technique in the vacuum. The atomic force microscopy confirms that nanoparticles of Ag were formed on the Co magnetic layer, and subsequently, the longitudinal Kerr signal of Cu/Co/Ag was amplified more than 2 times. This enhancement is resulting from the overlap of the surface plasmon resonance in the silver with the electronic transition in the Co layer. Furthermore, we investigated the effect of transparent semiconductor SnO₂ as a cap layer on the magnitude of longitudinal Kerr signal. To obtain the optimal thickness of cap layer, a numerical analysis was carried out using a 4 × 4 characteristic matrix, which takes into account multiple reflections from interfaces within the medium and light transmission through the layers.