Atomically Layered Structures for Perpendicular Magnetic Information Storage

1994 ◽  
Vol 343 ◽  
Author(s):  
Bruce M. Lairson ◽  
M. R. Visokay ◽  
R. Sinclair ◽  
S. M. Brennan ◽  
B. M. Clemens ◽  
...  
Keyword(s):  
Layered Structures ◽  
Information Storage ◽  
Magnetic Characteristics ◽  
Contact Probe ◽  
Modulated Structures ◽  
Bilayer Period ◽  
Random Alloys ◽  
Contact Recording ◽  
Probe Transducer ◽  
Magneto Optic

ABSTRACTLayered structures can possess a high volumetric density of interfaces, which can result in novel magnetic properties. We report magnetic characteristics of two types of atomically layered structures, (001) oriented intermetallics with the CuAu(I) crystal structure and (111) oriented artificial multilayers. C-axis oriented superlattices of PtFe, PtCo, PdFe and PdCo with the layered CuAu(I) structure, possess large magnetic anisotropies and novel magneto-optic properties relative to the corresponding random alloys. These films are produced by annealing, with tetragonality and magnetic anisotropy developing in a fashion which depends on the initial bilayer period and annealing parameters. (111) oriented artificially grown Pd/CoCr multilayers are reported for perpendicular magnetic recording applications. Using a perpendicular contact probe transducer, the multilayers exhibit two times the readback signal of CoCr media. The multilayers can be made with low roughness suitable for contact recording, and can generate narrow readback pulses with large amplitude. Many aspects of Pd/Co performance, such as overwrite, can be predictably optimized for a given set of transducer properties. The reported results show that compositionally modulated structures can be made which have a wide variety of useful properties for perpendicular hard disk and magneto-optic recording.

Large selective magneto-optic response from magnetic semiconducting layered structures

2000 ◽  
Vol 61 (16) ◽  
pp. R10571-R10574 ◽  
Author(s):  
Yu. A. Uspenskii ◽  
B. N. Harmon
Keyword(s):  
Layered Structures ◽  
Magneto Optic

Soft magnetic characteristics of Co/Zr thin‐film layered structures (abstract)

1991 ◽  
Vol 69 (8) ◽  
pp. 5367-5367
Author(s):  
A. P. Valanju ◽  
D. Y. Kim ◽  
R. M. Walser
Keyword(s):  
Thin Film ◽  
Layered Structures ◽  
Magnetic Characteristics ◽  
Soft Magnetic

Structure-Property Relationships in Sputtered Magneto-Optic Multilayers

1997 ◽  
Vol 3 (S2) ◽  
pp. 397-398
Author(s):  
R. Sinclair ◽  
G. A. Bertero ◽  
M.R. Visokay
Keyword(s):  
Polarized Light ◽  
Hysteresis Loops ◽  
Perpendicular Magnetic Anisotropy ◽  
High Resolution Electron Microscopy ◽  
Magnetic Multilayers ◽  
Information Storage ◽  
Inert Gases ◽  
Structure Property ◽  
Kerr Rotation ◽  
Magneto Optic

One technology for high-density information storage employs magneto-optic thin films. Key material properties include a large magneto-optic Kerr rotation of polarized light (especially in the blue wavelength range), high perpendicular magnetic anisotropy, good reflectivity and a large magnetic coercivity. These can be achieved in nano-scale magnetic multilayers (e.g., Co-Pt) in which one of the constituent layers is ferromagnetic. Naturally the magnetic properties can be manipulated to a great extent by the preparation conditions, and the microstructure is most readily revealed by cross-section high-resolution electron microscopy (HREM). In our work, extremely high quality multilayers were fabricated by sputtering using a variety of inert gases, and most notably the influence of interface sharpness on properties was assessed. Intermetallic compounds, which are essentially “natural” multilayers, were also extensively studied.Figure 1 shows magneto-optic Kerr rotation hysteresis loops for multilayers sputtered in 5 mtorr of either argon or the heavier xenon gas.

Surface Magnetism and Kerr Spectroscopy

MRS Bulletin ◽  
1995 ◽  
Vol 20 (10) ◽  
pp. 34-37 ◽  
Author(s):  
Z.Q. Qiu ◽  
S.D. Bader
Keyword(s):  
Giant Magnetoresistance ◽  
Polarized Light ◽  
Polarization Plane ◽  
Magnetic Surface ◽  
Information Storage ◽  
Antiferromagnetic Coupling ◽  
Dielectric Tensor ◽  
Surface Magnetism ◽  
Storage Media ◽  
Magneto Optic

Magneto-optic effects were first discovered in 1845 by Michael Faraday, but these effects continue to make a major impact on the materials community to this day. The need for new magnetic information-storage media has stimulated new approaches and opened new scientific opportunities in the exploration of thin-film and surface magnetism. This article provides background to some of these developments and highlights examples of contemporary issues that provide a focus for the field. In the Faraday effect, the polarization plane of linearly polarized light rotates when a magnetic field is applied in the propagation direction. The analogous phenomenon was subsequently discovered by the Rev. John Kerr in 1877 for light reflected from opaque materials. The works of Faraday and Kerr serve as cornerstones for our present understanding of magneto-optic effects in magnetic materials. Magnetooptics is presently described in the context of either microscopic quantum theory or macroscopic dielectric theory. Microscopically, the coupling between the electric field of the propagating light and the electron spin in a magnetic medium occurs through the spin-orbit interaction. Macroscopically, magneto-optic effects arise from the antisymmetric, off-diagonal elements in the dielectric tensor, as discussed in the next section.Magneto-optic characterizations of surface magnetism began only a decade ago. The first surface magneto-optic Kerr-effect study, better known by its acronym SMOKE, concerned the magnetichysteresis loops for ultrathin Fe films grown epitaxially on Au(100). Since then, SMOKE has emerged as a premier surface-magnetism technique. SMOKE has been applied to various topics in low-dimensional magnetism, ranging from the detection of magnetic order to the characterization of critical behavior, magnetic surface anisotropies, and the oscillatory antiferromagnetic coupling exhibited by giant-magnetoresistanceheterostructures. Additional interest in SMOKE has been generated by the recent commercialization of high-density, magneto-optic information-storage media, and especially by the next-generation candidate material based on Co/Pt superlattices.

scholarly journals Enhanced magneto‐optic Kerr effects in thin magnetic/metallic layered structures

1989 ◽  
Vol 55 (24) ◽  
pp. 2479-2481 ◽  
Author(s):  
William A. McGahan ◽  
Liang‐Yao Chen ◽  
Z. S. Shan ◽  
D. J. Sellmyer ◽  
John A. Woollam
Keyword(s):  
Layered Structures ◽  
Magneto Optic

MOPS, a magneto‐optic‐photoconductor sandwich for optical information storage

1977 ◽  
Vol 48 (1) ◽  
pp. 366-368 ◽  
Author(s):  
J.‐P. Krumme ◽  
H. Heitmann ◽  
D. Mateika ◽  
K. Witter
Keyword(s):  
Information Storage ◽  
Optical Information ◽  
Optical Information Storage ◽  
Magneto Optic

Fabrication and tuning soft magnetic and magneto-optical properties of BMGs based Fe-B-Nb-Ni transparent thin films, obtained by Pulsed Laser Deposition.

2014 ◽  
Vol 1649 ◽  
Author(s):  
Ansar Masood ◽  
A. A. Afridi ◽  
V. Ström ◽  
A. Riazanova ◽  
L. Belova ◽  
...  
Keyword(s):  
Film Thickness ◽  
Faraday Rotation ◽  
Laser Deposition ◽  
Visible Range ◽  
Magnetic Characteristics ◽  
Silicon Substrates ◽  
Soft Magnetic ◽  
Wide Range ◽  
Quartz Substrates ◽  
Magneto Optic

ABSTRACTWe have fabricated by pulse laser deposition very thin (∼5-7 nm) and thick (∼27-408 nm) films of composition Fe66B24Nb4Ni6 on silicon and quartz substrates respectively, and studied their magnetic and magneto-optic properties at room temperature. We find that the thicker films on silicon can be tuned by appropriate thermal annealing to exploit soft magnetic characteristics with low HC, and high MS values. The magnetic hysteretic loops of the as-deposited thicker films on silicon substrates show two interesting characteristics: 1) increase in the coercivity with the film thickness and 2) the onset of a two stage process during the approach to magnetic saturation. The initial in-plane characteristic of the hysteresis loop is followed by a linear anisotropic behavior between remanence and saturation- that changes into square soft-magnetic loops on decreasing the film thickness. By suitable annealing the intrinsic strain disappears at relatively low temperatures (≤200 oC); the thicker films can be tailored to exhibit a simple soft-magnetic square loop with low HC. The ∼5-7 nm films deposited on glass are transparent and have been investigated for their magneto-optic properties using Faraday rotation (FR) measurement technique. Very high values of FR in the range 4-20 deg/µm almost linearly dependent on the wavelength of light in the range 405-611 nm are observed. The observed high values of Faraday rotation over a wide range of wavelength of light are useful for the applications as magneto-optic sensors in the UV to visible range.

Materials for Electron Beam Information Storage

1969 ◽  
Vol 27 ◽  
pp. 152-153 ◽  
Author(s):  
D. E. Speliotis
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Recent Literature ◽  
Electron Beams ◽  
Information Storage ◽  
The Subject ◽  
The Magnetic Field

The interaction of electron beams with a large variety of materials for information storage has been the subject of numerous proposals and studies in the recent literature. The materials range from photographic to thermoplastic and magnetic, and the interactions with the electron beam for writing and reading the information utilize the energy, or the current, or even the magnetic field associated with the electron beam.

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