Linear and non-linear magneto-optical studies of Pt/Co/Pt thin films

Linear magneto-optical Kerr effect (MOKE) microscopy and magnetization-induced second-harmonic-generation (MSHG) magnetometry and imaging were used as two complementary optical techniques to measure the magnetic hysteresis loops and to visualize the domain structure in Pt/Co/Pt thin films with a weak uniaxial in-plane magnetic anisotropy. While the MOKE is used to probe the magnetization over the full thickness of the Co layer, MSHG is used to check the Co/Pt interfaces selectively. When the magnetic field H is not applied along the easy axis a, longitudinal MOKE and MSHG hysteresis loops exhibit different shapes. The differences between the longitudinal MOKE and MSHG magnetic pattern images for H∥a are only found in domain wall regions. All of these results are interpreted by considering transverse components of the non-linear optical polarization.

[1]  S. Kurimura,et al.  Application of the second harmonic generation microscope to nondestructive observation of periodically poled ferroelectric domains in quasi-phase-matched wavelength converters , 1997 .

[2]  K. Bennemann.  Nonlinear Optics in Metals , 1999 .

[3]  Ernesto E. Marinero,et al.  MOLECULAR-BEAM-EPITAXIAL GROWTH AND MAGNETIC PROPERTIES OF CO-PT SUPERLATTICES ORIENTED ALONG THE 001, 110, AND 111 AXES OF PT , 1990 .

[4]  V. Mathet,et al.  Morphology and magnetic properties of Pt/Co/Pt/Al2O3(0001) structures:: influence of the growth temperature , 1998 .

[5]  Pavlov,et al.  Determination of the magnetic symmetry of hexagonal manganites by second harmonic generation , 2000, Physical review letters.

[6]  Magnetization-induced second-harmonic generation enhanced by surface plasmons in ultrathin Au/Co/Au metallic films , 1999 .

[7]  Yaochun Shen.  Principles of nonlinear optics , 1984 .

[8]  A. Zayats,et al.  Near-field second-harmonic imaging of ferromagnetic and ferroelectric materials. , 1997, Optics letters.

[9]  T. Rasing,et al.  Theory of nonlinear magneto-optical imaging of magnetic domains and domain walls , 1997 .

[10]  Theo Rasing,et al.  A combined nonlinear and linear magneto-optical microscopy , 1997 .

[11]  M. Straub,et al.  Surface Magnetism of Ultrathin γ -Fe Films Investigated by Nonlinear Magneto-optical Kerr Effect , 1996 .

[12]  New nonlinear intensity Kerr effect in the polar geometry , 2000 .

[13]  W. B. Zeper,et al.  Perpendicular magnetic anisotropy and magneto-optical Kerr effect of vapor-deposited Co/Pt-layered structures , 1989 .

[14]  A. Bauer,et al.  In-plane magnetization of garnet films imaged by proximal probe nonlinear magneto-optical microscopy , 2000 .