1,721,160 research outputs found
Magnetic anisotropy and magneto-optical effects of (Pt/Co/Pt/Ni) multilayers
No full textDC magnetron sputter deposited (Pt/Co/Pt/Ni) multilayers which exhibited Curie temperatures in the range of 150-300 degrees C were studied as possible alternative multilayers for magneto-optical recording to the widely studied Co/Pt, whose Curie temperatures are in the range of 200-400 degrees C. These multilayers exhibited comparable magnetic and magneto-optical properties to Co/Pt multilayers with enhancement of the Kerr rotation at lower wavelengths and negligible Kerr ellipticity over a wide range of the spectrum. The dependence of the magnetic anisotropy on the thicknesses of nickel, cobalt, and platinum sublayers was studied. The surface anisotropies of nickel and cobalt were estimated as - 0.003 ergs/cm(2) and 0.027 ergs/cm(2) respectively and the total volume anisotropy due to Co and Ni is estimated as - 1.74 x 10(6) ergs/cm(3).Srinivas gratefully acknowledges KOSEF (Korea Science
and Engineering Foundation) and CISEM (Center for
Interface Science and Engineering of Materials) for providing
an opportunity to carry out this work and the financial
assistance
Magnetic and magneto-optical properties of Ni Pt multilayers with perpendicular magnetic anisotropy at room temperature
No full textThe magnetic and magneto-optical properties of Ni/Pt multilayers exhibiting square Kerr hysterisis loops at room temperature were studied. Squared polar Kerr hysterisis loops at room temperature in Ni/Pt multilayer thin films were obtained for the samples prepared by sequential DC magnetron sputter deposition of nickel and platinum with t(Ni) = 13-21 Angstrom and t(pt) = 3.5-7.5 Angstrom. The coercivity of these multilayers was in the range of 400-1100 Oe. The saturation magnetization was found to show an inverse dependence on the nickel sublayer thickness. About a monolayer of Ni at interface was observed to behave less magnetically than the interior Ni atoms. The polar Kerr rotation exhibited an increasing trend with decreasing wavelength in the spectral range of 7000-4000 A. The maximum of the polar Kerr rotation was found to shift to a higher wavelength with increasing nickel sublayer thickness. (C) 1999 Elsevier Science B.V. All rights reserved.We gratefully acknowledge the financial support from
the Creative Research Initiatives of the Ministry of
Science and Technology of Korea and Center for Interface Science and Engineering of Materials
Magnetic and magneto-optical properties of (Pt/Co/Pt/Ni) multilayers
No full textThe Curie temperatures of Co-based multilayers which find application as magneto-optical recording media, are much higher than the optimum writing temperature of about 200 degrees C. Alloying Co with nickel has been projected as a viable solution to reduce the Curie temperature. However, perpendicular magnetic anisotropy energy, magnetization, and magneto-optical properties decrease upon alloying. In a novel approach we attempted to combine the features of Co/Pt multilayers with those of low Curie temperature Ni/Pt multilayers to develop low Curie temperature (Pti/Co/Pt/Ni) multilayers. We have deposited (Pt/Co/Pt/Ni) multilayers by d.c. magnetron sputtering and studied their magnetic and magneto-optical properties. The Curie temperatures of these multilayers were in the range of 150-300 degrees C, which are much lower than those of Co/Pt and (Co,Ni)/Pt multilayers. The Kerr spectra of these multilayers show enhancement at lower wavelengths with maxima around 3000 Angstrom. The magnetization of these multilayers was comparable to that of Co/Pt multilayers. These multilayers with low Curie temperatures, enhanced Kerr rotation at lower wavelengths, reasonable coercivities appear to be very interesting for application to magneto-optical recording media.One of the authors GS gratefully acknowledges Korea
Science and Engineering Foundation and Center for Inter-
face Science and Engineering of Materials for providing
the financial assistance and an opportunity to carry out this
work
Novel (Pt/Co/Pt/Ni) multilayers for magneto-optical recording media
No full textThe sputter deposited (Pt/Co/Pt/Ni) multilayer films were studied as possible alternative low Curie temperature multilayers for magneto-optical recording. The Curie temperatures of these multilayers were found to be between 150 and 300 degrees C, which are much lower than those of Co/Pt multilayers or (Co,Ni)/Pt multilayers. The coercivities of these multilayers were between 450 and 800 Oe. The Kerr spectra of these multilayers exhibited enhancement of the Kerr rotation at lower wavelengths. These multilayers were found to show comparable magnetic and magneto-optical properties to Co/Pt multilayers and have an added feature of low Curie temperature making them attractive for magneto-optical storage applications. (C) 1996 American Institute of Physics.One of us (Srinivas) gratefully acknowledges KOSEF
(Korea Science and Engineering Foundation)for providing
an opportunity and financial assistance to carry out this
work
Magnetic and Magneto-optical Properties of Ni/Pt Multilayers with Perpendicular Magnetic Anisotropy at Room Temperature
No full textThe magnetic and magneto-optical properties of NilPt multilayers exhibiting square Kerr hysterisis loops
at room temperature were studied. Squared polar Kerr hysterisis loops at room temperature in NilPt
multilayer thin films were obtained for the samples prepared by sequential dc magnetron sputter
deposition of nickel and platinum with t"i = 13 - 21 Å and tpt 3.5. 7.5 Å. The coercivity of these
multilayers was in the range of 400 • 1100 Oe. The saturation magnetization was found to show an inverse
dependence on nickel sublayer thickness. About a monolayer of Ni at interface was observed to behave
less magnetically than the interior lii atoms. The polar Kerr rotation exhibited an increasing trend with
decreasing wavelength in the spectral ran앙e of 7000-4000 A. 1he maximum of polar Kerr rotation was
found to shift to higher wavelengths with increase in nickel sublayer thickness.We gratefully acknowledge the financial support from the Ministry of Science and Technology of Korea and Center for Interface Science and Engineering of Materials
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