27-01-2015, 07:42 PM
sir/madam here iam requesting you to access the ppt for reference to teach to the students of engineering as a teacher under the part of curriculum
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applications of magnetic materials ppt
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sir/madam here iam requesting you to access the ppt for reference to teach to the students of engineering as a teacher under the part of curriculum
23-03-2017, 12:17 PM
Intelligent magnetic materials are used in the manufacture of various applications, such as brakes and high-performance shock absorbers for civil engineering (bridges and buildings), electrical and industrial appliances (washing machines and gymnastics apparatus), medical devices (prostheses) and the automotive industry ( Automobiles and trucks). For example, the Audi Magnetic Ride are magnetic rheological dampers with an electronic control unit for the suspension that will automatically adjust its damping properties depending on the current road conditions and the way of driving.
During the last decade, many important advances have been made in electronics, semiconductor epitaxy, photonic devices, thin film metallurgy, and non-destructive characterization techniques to evaluate these new kinds of materials. This issue of JOM-e examines an exciting new area of activity undertaken by members of the TMS Electronic Magnetic and Photonic Materials Division: magnetic film materials for advanced electronic devices.
Thin films of magnetic materials can be used for high-speed read / write heads in disk memory devices or as permanent memory for computer applications. Devices such as these retain the state of the memory cell when the power is turned off, in contrast to the volatile memory in a standard dynamic RAM device. In addition, such memory must consume an insignificant amount of power when in operation, in contrast to the constant drain of semiconductor dynamic random access memory (DRAM).
The utility of this new class of magnetic materials is based on the giant magnetoresistive effect (GMR), identified in the late 1980s by Babich et al. And Sato et al. (See references in the two articles of this issue). By layering conductors with layers oriented to the domain of thin magnetic films, a large change of resistance can be induced in the conductor. This can be understood by the interaction of electric and magnetic fields in the current transport (the "right rule") and Maxwell's equations. The GMR effect produces a relatively large signal when properly incorporated into a layered device structure, making it very attractive for commercial applications. Understanding the GMR effect has led to several device constructs, but absolute signal levels are still quite small, making processing, testing and application robustness difficult.
Recent findings have shown that by modifying magnetic materials, layering, and chemical makeup, substantially higher performance structures can be created that overcome the limitations of simple GMR-based devices. These devices are based on thin films of NiFe and are characterized as tunneling devices, where a current is forced through a nominally non-conductive material, such as a very thin oxide layer, while interacting with magnetic fields of various orientations.
We present here two contributions from both industrial and academic viewpoints discussing deposition methods for bonding magnetic tunnels (MTJ) and GMR films, the manufacture of MTJ devices and characterization methods for extremely thin nanostructured magnetic film materials. Some of the critical layers in a MTJ are of the order of 1-2 nm, which requires very precise and powerful characterization tools for the evaluation.
The first work comes from an advanced technology research group at the Motorola Physical Sciences Research Laboratory, which investigates MTJ materials for high speed magnetic access memory (MRAM) devices. Slaughter et al. They present an analysis of a multilayer stack of thin magnetic films coupled with a dielectric tunnel layer. In its structure, the current flow is modulated through the precisely controlled dielectric layer by means of tunneling processes. They have become even more responsive in their MTJ devices than reported GMR devices. The key feature in his work is the interaction of a fixed orientation magnetic layer with a variable orientation magnetic layer that produces the nature 0 or 1 for the memory cell. The authors describe some of the problems in the creation and fabrication of devices and the characterization of thin layers of materials by non-destructive methods.
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