Fabrication and characterization of Bi-substituted yttrium iron garnet films by pulsed laser deposition

Abstract

We have systematically investigated the effects of processing parameters, including various oxygen pressures (Po-2) ranging from 200 to 1000 mTorr and substrate temperatures (T,) ranging from 500 to 750degreesC, on the characteristics of Bi-substituted yttrium. iron garnet (Bi:YIG) films grown on (111) gadolinium gallium garnet (GGG) substrates. Bi:YIG films were grown using a pulsed laser deposition method with an ArF excimer laser (lambda=193 nm). Although the compositions of all the Bi:YIG films grown at the constant T, of 600degreesC were close to the target composition irrespective Of Po-2, the Bi contents were slightly increased with increasing Po-2, which was consistent with the variation in Faraday rotation angles (OF). In addition, the crystallinity of the Bi:YIG films was deteriorated with increasing Po-2, and their grains became irregular. At T, above 700degreesC, Bi-deficient yttrium iron garnet films were grown. Consequently, high quality epitaxial Bi:YIG films exhibiting Faraday rotation angles of -1.0similar to-1.5 degree/mum were successfully grown at the substrate temperatures in the range of 500similar to650degreesC when the Po-2 of 200 mTorr was used.