Microwave and magneto-optic properties of pulsed laser deposited bismuth iron garnet films

We report on processing and comparative characterization of epitaxial Bi₃Fe₅O₁₂ (BIG) films grown by pulsed laser ablation of a precursor oxide target onto (NdGd)₃ (ScGa)₅O₁₂ [NGSGG(111)] and Gd₃(ScGa)₅O₁₂ [GSGG(001)] single crystals. Comprehensive X-ray diffraction analyses reveal the epitaxial quality of the BIG films: they are single phase, exclusively (111) and (001) oriented with less than 0.4° and 0.06° of the full width at half maximum of the rocking curve of main texture Bragg reflection [(111) for NGSGG and (001) for GSGC substrate, respectively]. The films are strongly in-plane textured with cube-on-cube film-to-substrate epitaxial relationship. VSM and ferromagnetic resonance measurements revealed in-plane magnetization in BIG/GSCG(001) film, while the BIG/NGSGG(111) film was found to have perpendicular magnetization. For BIG(001) and (111) films the saturation magnetization 4πM_s was found to be 1400 and 1200 Gs; the Faraday rotation at 635 nm was -7.8 and -6.7 deg/μm; the constant of uniaxial magnetic anisotropy was K_u*=-8.70×10⁴ and +1.16×10⁴ erg/cm³; the constant of cubic magnetic anisotropy K ₁=-3.6×10³ and -7.14×10³ erg/cm³. High Faraday rotation and low coercive field (⩽40 Oe) of BIG/GSGG(001) films show promise for their use in integrated magneto-optic applications