https://shell.cas.usf.edu/~phanm//PMS.pdf

Giant magnetoimpedance materials: Fundamentals and applications

This paper proposes a new approach to magnetic recording based on shingled writing and two-dimensional readback and signal-processing. This approach continues the use of conventional granular media but proposes techniques such that a substantial fraction of one bit of information is stored on each grain. Theoretically, areal-densities of the order of 10 Terabits per square inch may be achievable. In this paper we examine the feasibility of this two-dimensional magnetic recording (TDMR) and identify the significant challenges that must be overcome to achieve this vision.

The Feasibility of Magnetic Recording at 10 Terabits Per Square Inch on Conventional Media

Over the past few years, the scientific community, as well as the world's coatings industry has seen the introduction of oxide/polymer-based superhydrophobic surfaces and coatings with exceptional water repellency. Online videos have caught the public's imagination by showing people walking through mud puddles without getting their tennis shoes wet or muddy, and water literally flying off coated surfaces. This article attempts to explain the basics of this behavior and to discuss and explain the latest superhydrophobic technological breakthroughs. Since superhydrophobic surfaces and coatings can fundamentally change how water interacts with surfaces, and the fact that earth is a water world, it can legitimately be said that this technology has the potential to literally change the world.

https://iopscience.iop.org/article/10.1088/0034-4885/78/8/086501/pdf

Superhydrophobic materials and coatings: a review

https://cyberleninka.org/article/n/596.pdf

Corrosion behavior of superhydrophobic surfaces: A review

Permanent magnet applications

The development of magnetic field sensors for biomedical applications primarily focuses on equivalent magnetic noise reduction or overall design improvement in order to make them smaller and cheaper while keeping the required values of a limit of detection. One of the cutting-edge topics today is the use of magnetic field sensors for applications such as magnetocardiography, magnetotomography, magnetomyography, magnetoneurography, or their application in point-of-care devices. This introductory review focuses on modern magnetic field sensors suitable for biomedicine applications from a physical point of view and provides an overview of recent studies in this field. Types of magnetic field sensors include direct current superconducting quantum interference devices, search coil, fluxgate, magnetoelectric, giant magneto-impedance, anisotropic/giant/tunneling magnetoresistance, optically pumped, cavity optomechanical, Hall effect, magnetoelastic, spin wave interferometry, and those based on the behavior of nitrogen-vacancy centers in the atomic lattice of diamond.

Ultrasensitive Magnetic Field Sensors for Biomedical Applications.

Asymmetrical giant magnetoimpedance (AGMI), which utilizes a high frequency bias field hb, is realized in a Co-based amorphous wire having a circumferential anisotropy in the outer region No asymmetry in the dc magnetic configuration is needed in this case AGMI is discussed in terms of the surface impedance tensor, demonstrating that the effect of hb is related to the role of the off-diagonal component of the impedance in the voltage response measured across the wire This effect is important for developing autobiased linear magnetic sensors Using two oppositely biased wires, a near-linear voltage output (±4 mV) is obtained in the range of ±5 Oe for the sensed dc field at a frequency of 8 MHz

Asymmetrical magnetoimpedance in as-cast CoFeSiB amorphous wires due to ac bias

In planar structures, magnetization patterns exist that have the surprising property that all the external fringing field of flux emerges from one side of the structure, with precisely none appearing on the other side. In the last 25 years, this fact has led to a number of useful applications. More recently, the same concept has been found to hold for both cylindrical and spherical hollow structures, where all the fringing flux emerges either inside or outside the structure, with precisely none appearing on the other side. Again, this has led to a number of important practical applications. While many of the concepts have been published previously, this paper contains, for the first time, a uniform mathematical analysis of these one-sided flux configurations. Additionally, the paper reviews the principal applications of one-sided flux structures.

One-sided fluxes in planar, cylindrical, and spherical magnetized structures

Three-dimensional (3-D) finite element models have been utilized to simulate electromagnetic behaviors in spin-tunneling random access memory (STram). The most significant contributors have been identified. Compared with conventional current-in-plane (CIP) giant magneto-resistive (GMR) memory, whose signal level is inversely proportional to the square root of the storage density, these current-perpendicular-to-plane (CPP) STram elements provide an excellent readout property in that their signal level is independent of their cross-section area. This result is so attractive that the density of STram should not be limited by signal degradation. Moreover, a magnetic flux closure design was found to reduce the crossfeed by about a factor of five, compared with conventional keeperless design, which is the most favored approach for achieving 10/sup 9/ bits/cm/sup 2/ areal density. Although the storage mechanism described in this paper is made of STram, the flux-closure design could be generally applicable to other magnetic solid state memories.

Feasibility of ultra-dense spin-tunneling random access memory

This article concerns the effect of the in-plane film size on the magnetoimpedance (MI) characteristics in magnetic/metallic multilayers. The problem is approached by a two-dimensional solution of the Maxwell equations in a symmetrical three-layer film. If the edge effect is neglected, the magnetic flux generated by the current flowing through the film is confined within the outer magnetic layers. In a finite width sandwich, the flux leaks through the inner conductor. This process eventually results in a considerable drop in MI ratio if this width is smaller than the critical flux decay length depending on the effective transverse permeability, layer thickness, and frequency.

Desmond J. Mapps

Papers

Ultrasensitive Magnetic Field Sensors for Biomedical Applications.

Asymmetrical magnetoimpedance in as-cast CoFeSiB amorphous wires due to ac bias

One-sided fluxes in planar, cylindrical, and spherical magnetized structures

Feasibility of ultra-dense spin-tunneling random access memory

Two-dimensional analysis of magnetoimpedance in magnetic/metallic multilayers