Comparison of Bi3Fe5O12 film giant Faraday rotators grown on (111) and (001) Gd3Ga5O12 single crystals

• Bismuth iron garnet (Bi3Fe5O12, BIG) epitaxial thin films were grown on single crystal (Gd3Ga5O12, GGG) (111) and (001) substrates by rf-magnetron sputtering technique. Processing parameters have been optimized to obtain high deposition rate (2.74 mu m/h) and the surface rms roughness less than 10 nm. X-ray diffraction reveals films epitaxial quality: exclusive (111) or (00 1) orientation with narrow rocking curves and strong in-plane texture. Films possess low optical loss and magneto-optical Faraday rotation (FR) as high as 5 deg/mu m at 677 nm wavelength. Comparative analysis of films grown on (111) and (001) substrates clearly shows significant superiority of BIG/GGG(001) film. For this film, the coercive field similar to 100 Oe appears to be 2.5 times lower while the optical transmission to be 10% higher than that for BIG/GGG(111) film. Enhanced magneto-optical performance of BIG/GGG(001) films relies upon better accommodation of the film-to-substrate mismatch strain through the tetragonal BIG lattice distortions compared to the rhombohedral one in BIG/GGG(111) films.

Subject headings

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

Keyword

magnetooptical effects

theory

models

and numerical simulation

optical constants (refractive index

absorption)

deposition by sputtering

ferrite and garnet devices

iron-garnet

rotation

Publication and Content Type

ref (subject category)

art (subject category)