Magnetic and magneto-optic properties of pulsed laser deposited Ce_xY_3-xFe₅O₁₂ films

We present experimental studies of crystalline, magnetic, and magneto-optic (MO) properties and their correlation with the processing parameters of Ce-substituted yttrium iron garnet (Ce_xY_3-xFe₅O₁₂) thin films grown epitaxially onto single crystal Gd₃Ga₅O₁₂(111) substrates by Nd:YAG pulsed laser deposition technique. Rutherford backscattering (RBS) analysis and microprobe energy dispersive spectrometry (EDS) prove the background oxygen pressure, used for films growth, control films stoichiometry. Oxygen ambient pressure appears to be an important parameter to grow Ce_xY_3-xFe₅O₁₂ films with good crystallinity, magnetic properties, as well as enhanced MO effect. It is found that the film fabricated at 50 mTorr oxygen pressure exhibits a maximum Faraday rotation (FR) θ_F = 1.78 deg/μm at λ = 633 nm, a maximum saturation magnetization 4πM_s = 1255 Gauss with a minimum in-plane coercivity H_c = 35 Oe, and the narrowest full width at half maximum FWHM = 0.06° of the (444) Bragg reflection rocking curve. The analog of the Verdet constant V = θ_F/4πM_s, also found to be dependent on the oxygen ambient pressure, reaches the value as high as 1.4 deg/μm·kG at 633 nm, suggesting that this material is useful for MO applications.