Bi3Fe5O12 thin film visualizer

Micrometer thick Bi-3 Fe-5 O-1.2 (BIG)(001) films were grown onto Gd-3(ScGa )(5)O-12(001) single crystals by the pulsed laser deposition technique. The films are of epitaxial quality with a lattice constant of 1.263 nm. Narrow x-ray rocking curves (full width at half maximum: 0.06 deg) and narrow fer romagnetic resonance lines (widths of 25 Oe) indicate good crystalline qual ity and magnetic performance. The films possess in-plane magnetization, Far aday rotation as high as -7.8 deg/mum at 630 nm wavelength, and the magneti zation M-H curves are linear in the field range from -1.6 kOe to +1.6 kOe. The magneto-optical (MO) properties are almost temperature independent betw een 5 K and 200 K. This enables the use of thin BIG films as visualizers of magnetic fluxes in high-T-c superconductors. Magnetic fluxes have been vis ualized in YBa2Cu3O7-infinity, (YBCO) ceramics with an artificial grain bou ndary. The sensitivity expressed as Faraday rotation angle (per film thickn ess) per magnetic field unit was found to be 4.9 deg/(kOe . mum) in a 730 n m thick BIG film.