Optical and magneto-optical properties of magnetic nanocomposites FePt-SiO2.

Authors :: Gan'shina, E.
Aimuta, K.
Granovsky, A.
Kochneva, M.
Sherbak, P.
Vashuk, M.
Nishimura, K.
Inoue, M.
Source :: Journal of Applied Physics; 6/1/2004, Vol. 95 Issue 11, p6882-6884, 3p, 5 Graphs
Publication Year :: 2004
Abstract: Structural, magnetic, magnetotransport, optical, and magneto-optical properties of (FePt)<subscript>1-X</subscript>(SiO<subscript>2</subscript>)<subscript>X</subscript> thin films in as-deposited state and after annealing were investigated. Magneto-optical properties were measured in the transversal Kerr effect (TKE) geometry. Magneto-optical spectra in nanocomposites (FePt)<subscript>1-X</subscript>(SiO<subscript>2</subscript>)<subscript>X</subscript> depend greatly on volume fraction of metal and annealing conditions. The TKE reaches the maximum value for compositions close to the percolation threshold X≈57% in as-deposited samples, as well as a maximum of the magnetoresistance. After annealing at 700 °C the TKE value significantly increases and the maximum of the magneto-optical response is observed at X≈70%. The magneto-optical spectra transformation after annealing is mainly due to the disorder-order phase transitions in FePt granules, changes in the mean granular size, and alloy microstructure. The TKE spectra calculated in the framework of the effective medium approximation for as-deposited samples are in good agreement with the experiment. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]