Nonlinear magneto-optical kerr effect and plasmon-assisted SHG in magnetic nanomaterials exhibiting giant magnetoresistance

Abstract

Optical second harmonic generation (SHG) and nonlinear magneto-optical Kerr effect (NOMOKE) are experimentally studied in CoxAg1-x and (CoFe)(x)(Al2O3)(1-x) granular films which exhibit giant magnetoresistance (GMR) effect. Nonmonotonous dependences of the magnetoresistance, SHG intensity and NOMOKE magnetic contrast on volume fraction of the magnetic component x are found. The maximum of the NOMOKE magnetic contrast is attained at the value of x close to that providing the maximum of the magnetoresistance. The resonances observed in the SHG spectra are associated with the local surface plasmon modes at the granule/host interfaces. (C) 2001 Elsevier Science B.V. All rights reserved.