A New Class of Materials for Magneto-Optical Applications : Transparent Amorphous Thin Films of Fe-B-Nb and Fe-B-Nb-Y Metallic Glassy Alloys

• Optically highly transparent, soft magnetic thin films (4-18 nm thick) of Fe-B-Nb- and Fe-B-Nb-Y-based glassy metal targets were grown on quartz substrates by pulsed laser deposition, and their optical and magneto-optical properties were investigated over the visible spectrum (400-700 nm). All the films found to be fully amorphous in structure were continuous with uniform thickness and surface morphology. Their optical transmittance in the range 50%-85% was found to be film thickness dependent over the entire visible regime. The Verdet constant (V) and Faraday rotation angle (theta(f)) for different films (similar to 4-18 nm) investigated as a function of wavelength (lambda) show considerably higher values for the films of Fe-B-Nb-Y alloy as compared with those for Fe-B-Nb films, e. g., the similar to 4 nm film of Fe-B-Nb-Y alloy exhibits V similar to 49 degrees/Oe cm and theta(f)similar to 26 degrees/mu m while it decreased to similar to 29.4 degrees/Oe and similar to 11.8 degrees/mu m, respectively, for the Fe-B-Nb alloy at lambda=611 nm. A linear relationship is found for the wavelength dependence of V and theta(f) for both alloy systems. To the best of our knowledge, these values are considerably higher than those reported for any other magneto-optic material. The films are found to be soft magnetic with a high saturation moment while their magnetic coercivity values increases with thinness of the films. The observed combination of optical and magneto-optical properties of this new class of amorphous metallic films makes them viable for multifunctional magneto-optical applications.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

Nyckelord

Amorphous magnetic materials

Faraday rotation

pulsed laser deposition (PLD)

soft magnetic thin films

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