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Open Access. Powered by Scholars. Published by Universities.®

1994

Roger Kirby Publications

Articles 1 - 6 of 6

Full-Text Articles in Physics

Magneto-Optical And Structural Properties Of Bialdylg/Fe Multilayers, J. X. Shen, Kurt W. Wierman, Y. B. Zhang, Roger D. Kirby, John A. Woollam, David J. Sellmyer May 1994

Magneto-Optical And Structural Properties Of Bialdylg/Fe Multilayers, J. X. Shen, Kurt W. Wierman, Y. B. Zhang, Roger D. Kirby, John A. Woollam, David J. Sellmyer

Roger Kirby Publications

Bi- and Al-doped DyIG(y Å)/Fe(x Å) (y = 50 to 130 Å and x = 5 to 15 Å ) multilayer thin films were made by magnetron sputtering onto Si(111) substrates. Rapid thermal annealing was used to crystallize these garnet multilayers. The crystallized multilayer samples possess well-defined interfaces. Atomic force microscopy showed that the annealed samples had smooth surfaces, with small grain sizes (~30 to 80 nm). All of the samples had perpendicular magnetic anisotropy with very square hysteresis loops. The coercivity was found to vary from 600 Oe to 2 kOe, depending on Fe thickness and annealing conditions ...


Magnetic And Magneto-Optic Properties Of Sputtered Co/Ni Multilayers, Y. B. Zhang, P. He, John A. Woollam, J. X. Shen, Roger D. Kirby, David J. Sellmyer May 1994

Magnetic And Magneto-Optic Properties Of Sputtered Co/Ni Multilayers, Y. B. Zhang, P. He, John A. Woollam, J. X. Shen, Roger D. Kirby, David J. Sellmyer

Roger Kirby Publications

We have investigated the magnetic and magneto-optic properties of Co/Ni multilayers deposited on Ag and Au buffer layers. The samples with Au buffer layers show perpendicular magnetic anisotropy, but those with Ag buffer layers do not. The. structure and degree of crystalline alignment of the buffer layer are evidently crucial to development of perpendicular magnetic anisotropy. We also present the results of polar Kerr rotation measurements as a function of wavelength and layer thickness of the multilayers.


Temperature-Dependent Interface Magnetism And Magnetization Reversal In Co/Pt Multilayers, Z. S. Shan, J. X. Shen, Roger D. Kirby, David J. Sellmyer, Y. J. Wang May 1994

Temperature-Dependent Interface Magnetism And Magnetization Reversal In Co/Pt Multilayers, Z. S. Shan, J. X. Shen, Roger D. Kirby, David J. Sellmyer, Y. J. Wang

Roger Kirby Publications

We report on the temperature dependence of the magnetic properties and interface magnetism of Co/Pt multilayers. The magnetic properties including magnetization and anisotropy change substantially as the temperature varies from 300 to 10 K for samples with Co layer thickness in the range from 3 to 7 Å. The interface anisotropy of about 0.38 erg/cm2 is nearly independent of temperature. The magnetization reversal is dominated by domain wall motion for the thinner Co layers and dominated by nucleation for the thicker Co layers.


Low-Temperature Characterization Of The Magnetic Properties Of Mnbial Thin Films, Kurt W. Wierman, J. X. Shen, Roger D. Kirby, David J. Sellmyer May 1994

Low-Temperature Characterization Of The Magnetic Properties Of Mnbial Thin Films, Kurt W. Wierman, J. X. Shen, Roger D. Kirby, David J. Sellmyer

Roger Kirby Publications

The magnetic properties of thin-film samples of MnBi0.8Alx with aluminum concentrations of x = 0.0, 0.4, 0.6, and 0.8 were systematically studied over a temperature range of 20 to 300 K. The as-deposited films are amorphous and nonmagnetic, but highly textured polycrystalline films that are ferromagnetic are formed by annealing at 350 °C. Our measurements show that the coercivity of such films rapidly decreases, then approaches a constant value (4 kOe for x = 0.4) with increasing annealing time. Magnetic measurements show that both anisotropy and coercivity decrease with decreasing temperature. Unlike bulk ...


Magnetization Reversal In Compositionally Modulated Tb/Fe Multilayers (Abstract), Roger D. Kirby, J. X. Shen, David J. Sellmyer May 1994

Magnetization Reversal In Compositionally Modulated Tb/Fe Multilayers (Abstract), Roger D. Kirby, J. X. Shen, David J. Sellmyer

Roger Kirby Publications

We have prepared compositionally modulated Tb(X Å) thin film multilayers with X ranging from 3.5 to 7 Å by magnetron sputtering on glass substrates. Magnetization measurements using SQUID and alternating gradient force magnetometers show that these samples have uniaxial anisotropies (Ku) up to 107 erg/cm3 and saturation magnetizations (Ms) between 50 and 350 emu/cm3. Constant field magnetization reversal measurements at room temperature show that these samples reverse by slow nucleation followed by relatively rapid domain wall motion. The samples with larger uniaxial anisotropies and smaller saturation magnetizations reverse completely for applied ...


Electronic Structure And Magneto-Optical Properties Of Mnbi And Mnbial, Sitaram Jaswal, J. X. Shen, Roger D. Kirby, David J. Sellmyer Apr 1994

Electronic Structure And Magneto-Optical Properties Of Mnbi And Mnbial, Sitaram Jaswal, J. X. Shen, Roger D. Kirby, David J. Sellmyer

Roger Kirby Publications

MnBiAl films are of considerable current interest for possible magneto-optical applications because of their perpendicular anisotropy, large polar Kerr rotation, reduced grain size, and structural stability. We report here experimental and theoretical studies of the effect of Al alloying on the electronic structure and magneto-optical properties of MnBi. Our measured spectral dependencies of the polar Kerr rotation in the two systems are similar. We carried out relativistic self-consistent spin-polarized electronic structure calculations on MnBi and MnBiAl, and the calculated densities of states are in good agreement with available x-ray photoemission spectroscopy data for both materials. The spin magnetic moment of ...