Dynamics of perpendicular recording heads

3D modeling and inductance measurements were used to design an ultra-high frequency perpendicular system. Kerr microscopy and spin-stand experiments with focused ion beam (FI-B) trimmed perpendicular heads and perpendicular media directly verified the high frequency concepts

Nanoscale recording transducer for perpendicular magnetic recording

A study of a perpendicular magnetic recording transducer with the potential to be utilized at areal densities above 1 Tbit ∕ in. 2 is presented. Focused ion beam etching is used to fabricate the transducer via trimming of a regular nanoslider ring head from an air bearing surface. The transducer is compared with a regular ring-type head. With spinstand experiments, it is demonstrated that the overlapping width determines the effective trackwidth in the case of the transducer. With other conditions equal, the transducer indicates substantially higher efficiency. The saturation current values for the transducer and the ring head are measured to be above 350 and 800 mA turn , respectively. The performance of the transducer is tested with two types of perpendicular recording media, with and without a soft underlayer, respectively. The experiments indicate that, contrary to the common belief, the medium without a soft underlayer demonstrates the potential for achieving substantially higher areal densities

Atmospheric correction of ocean color imagery through thick layers of Saharan dust

International audienceAirborne plumes of desert dust from North Africa are observable all year on satellite images over the Tropical Atlantic. In addition to its radiative impact, it has been suggested that this mineral dust has a substantial influence on the marine productivity. This effect is however difficult to gauge because present atmospheric correction algorithms for ocean color sensors are not capable of handling absorbing mineral dust. We apply a new approach to atmospheric correction in which the atmosphere is removed and the case 1 water properties are derived simultaneously. Analysis of SeaWiFS images acquired off Western Africa during a dust storm demonstrates the efficacy of this approach in terms of increased coverage and more reliable pigment retrievals

Physics considerations in the design of three-dimensional and multilevel magnetic recording

The purpose of this paper is to explore three-dimensional magnetic recording as a next generation recording technology. To defer the superparamagnetic limit in magnetic recording substantially beyond the 1 Tbit ∕ in. 2 mark, it is proposed to stack magnetic bits in a third (vertical) dimension. The vertical stacking underlies the concept of three-dimensional (3D) magnetic memory and recording-the primary subject of this paper. A clear distinction between absolute 3D memory and its trivial multilevel implementation is drawn. The paper focuses on the study of the media design and write and read processes. To minimize the intersymbol interference and improve stability, it is proposed to pattern the recording media in all three dimensions. Basic Co ∕ Pd -based 3D recording media necessary for this study are fabricated using cosputter deposition. Focused-ion-beam-based fabrication is used to pattern the recording media into nanoscale bit cells. The physics of 3D magnetic recording is also investigated theoretically with Landau-Lifshits-Gilbert-based micromagnetic modeling. The ultimate goal of this paper is to help understand the physics of 3D and multilevel magnetic recordings and trigger wide interest in the studied concept

Protein-based disk recording at areal densities beyond 10 terabits/in.(2)

The concept of optical protein-based memory has been of interest since the early 1970s. Yet, no commercially available protein-based memory devices exist. This review presents an analysis of the main challenges associated with the practical implementation of such devices. In addition, the discussion includes details on the potential of using the unparalleled properties of photochromic proteins by creating an optical data storage disk drive with unmatched features and, particularly, record-high data densities and rates

Focused Ion Beam as a Nanofabrication Tool for Rapid Prototyping of Nanomagnetic Devices

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 200

Patterned Soft Underlayers for Perpendicular Magnetic Recording

This paper will present an unconventional way to answer the above questions. In contrast to the conventional flat geometry of SUL, it is proposed to use a patterned SUL. FEM-based simulations will be performed to illustrate many key benefits of the use of a patterned SUL

Perpendicular Recording with Reduced Skew Angle Sensitivity

A detailed analysis to the problem of skew angle sensitivity in perpendicular magnetic recording is presented. A proposed analytical model is supported by numerical simulations with a commercial boundary element software program. According to the presented equivalent magnetic circuit model, a single pole recording head with a laminated composition involving two layers of different magnetic materials could be used to localize adequately strong magnetic field in the vicinity of the trailing edge of the recording head. It is shown that the recording field generated under each lamination layer is proportion to the relative magnetic permeability of the respective layer. Such localization of the magnetic flux results in substantially reduced skew angle sensitivity

Focused-ion-beam-fabricated nanoscale magnetoresistive ballistic sensors

In this letter, authors demonstrate magnetoresistance of the order of 18% at room temperature for a focused-ion-beam-fabricated nanoconstriction with critical dimensions of the order of 35 nm . The main purpose of this work is to show that focused ion beam (FIB)-fabricated nanoconstrictions are relatively reproducible and thus could be further developed to obtain substantially larger magnetoresistance. Magnetoresistance is expected to increase if critical dimensions of nanoconstrictions are further reduced. The proposed focused-ion-beam-fabricated nanoconstrictions could be also used as devices to study the electron "ballistic" regime in the emerging fields of Spintronics and magnetoresistive random access memory (MRAM)