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	Giant magnetoresistive effect - Wikipedia, the free encyclopedia
		The Giant Magnetoresistance Effect (GMR) is a quantum mechanical effect observed in thin film structures composed of alternating ferromagnetic and nonmagnetic metal layers.
		The effect manifests itself as a significant decrease in resistance from the zero-field state, when the magnetization of adjacent ferromagnetic layers are antiparallel due to a weak anti-ferromagnetic coupling between layers, to a lower level of resistance when the magnetization of the adjacent layers align due to an applied external field.
		Granular GMR is an effect that occurs in solid precipitates of a magnetic material in a non-magnetic matrix.
	en.wikipedia.org /wiki/Giant_magnetoresistive_effect (695 words)

	Giant magnetoresistive effect sensor, particularly having a multilayered magnetic thin film layer - Patent 5648885
		Magnetoresistive (MR) sensors have been known to employ the anisotropic magnetoresistive (AMR) effect in which a component of the resistance in the sensor varies in proportion to the square of the cosine of the angle between the magnetization of the sensor and the direction of sense current flowing through the sensor.
		The above-mentioned article "Giant Magnetoresistance: A Primer" states that to obtain a GMR effect, it is necessary that the thickness of the thin film layers must be less, preferably a fraction, of the mean free path of an electron in the array of thin film ferromagnetic layers separated by the thin film non-magnetic layer.
		Increasing the nickel content causes two effects: the first effect is to reduce the saturation magnetization of the second magnetic thin film layer 27; and the second effect is that of improving the texture of all the layers.
	www.freepatentsonline.com /5648885.html (7364 words)

	Magnetic field sensor with augmented magnetoresistive sensing layer - Patent 6872467
		The giant magnetoresistive effect has a magnetization dependent component of resistance that varies as the cosine of the angle between magnetizations in the two ferromagnetic thin-films on either side of an intermediate layer.
		Exhibiting the giant magnetoresistive effect in a superlattice structure, or in an abbreviated superlattice structure formed by a three layer "sandwich" structure, requires that there be arrangements in connection therewith that permit the establishment alternatively of both parallel and antiparallel orientations of the magnetizations in the alternate ferromagnetic thin-film layers therein.
		Patterned, micron-size exchange biased spin-valve sensors exhibit quite different giant magnetoresistance effect responses as compared to the stack of sheet films from which the sensors are formed by patterning due to the strong magnetostatic interaction between the ferromagnetic layers in the resulting patterned sensors.
	www.freepatentsonline.com /6872467.html (9393 words)

	The Ultimate Giant magnetoresistive effect Dog Breeds Information Guide and Reference
		The Giant Magnetoresistive Effect (GMR) is a quantum mechanical effect observed in thin film structures composed of alternating ferromagnetic and nonmagnetic layers.
		The effect manifests itself as a significant increase in resistance of the structure when two ferromagnetic layers contain electrons with opposite spin, compared to a lower level of resistance when the two layers contain electrons with parallel spin.
		The possibilities of using the effect in a magnetic field sensor, and hence as a new type of reading head in a computer hard drive, were quickly recognised by an IBM research team led by Stuart Parkin, who replicated the effect in polycrystalline layers.
	www.dogluvers.com /dog_breeds/Giant_magnetoresistive_effect (347 words)

	Spintronics - Wikipedia, the free encyclopedia
		The most common application of this effect is a giant magnetoresistance (GMR) device.
		This is a vast improvement over the anisotropic magnetoresistance effect in single layer materials which is usually less than 3%.
		Spin valves can be designed with magnetically soft free layers which have a sensitive response to very weak fields (such as those originating from tiny magnetic bits on a computer disk), and have replaced anisotropic magnetoresistance sensors in computer hard disk drives heads since the late 1990s.
	en.wikipedia.org /wiki/Spintronics (777 words)

	GMR - Head Technology
		The technology is named for the giant magnetoresistive effect, first discovered by two European researchers -- Peter Gruenberg and Albert Fert -- in the late 1980s.
		Giant magneto resistance (GMR) is a rapidly growing area of interest because researchers study new methods for increasing the memory capacity (gigabytes) of a hard-drive within a small area.
		This head is less expensive to produce, because it requires fewer process steps; and, it performs better in a drive, because the distance between the read and write elements is less.
	www.personal.psu.edu /users/s/b/sbk142/gmr.htm (354 words)

	CMS
		The "giant magnetoresistive" (GMR) effect was discovered in the late 1980s by two European scientists working independently: Peter Gruenberg of the KFA research institute in Julich, Germany, and Albert Fert of the University of Paris-Sud.
		These experiments were performed at low temperatures and in the presence of very high magnetic fields and used laboriously grown materials that cannot be mass-produced, but the magnitude of this discovery sent scientists around the world on a mission to see how they might be able to harness the power of the Giant Magnetoresistive effect.
		When a weak magnetic field, such as that from a bit on a hard disk, passes beneath such a structure, the magnetic orientation of the unpinned magnetic layer rotates relative to that of the pinned layer, generating a significant change in electrical resistance due to the GMR effect.
	www.cms.tuwien.ac.at /gmr.html (616 words)

	IBM Research \| Press Resources \| Giant Magnetoresistive effect
		Micrograph of one of IBM’s pioneering giant magnetoresistive (GMR) heads, the most sensitive of its kind for writing and reading data on a computer’s magnetic hard disk drive.
		By passing a pattern of current pulses through the large coil in the center of the image, magnetic fields are induced and concentrated at a tiny gap, located beneath the tip in the lower center.
		In modern disk drives using the IBM innovations of magnetoresistive (MR) or giant magnetoresistive (GMR) heads, the bits are written and read by separate elements in a recording head as it flies over the spinning disk.
	domino.research.ibm.com /comm/pr.nsf/pages/rsc.gmr.html (1581 words)

	ghow (Site not responding. Last check: 2007-11-04)
		IBM's disk storage revolution stems from the "giant magnetoresistive" (GMR) effect, discovered in the late 1980s by two European scientists.
		In essence, the GMR effect demonstrated large resistance changes in a magnetic field for certain materials composed of alternating thin layers of various metallic elements.
		The solution, again related to the GMR effect, was "spin valves," where the very small fields from the tiny bits rotates the magnetization direction in an "unpinned" magnetic layer in relation to a the magntization direcrion of a "pinned" magnetic layer.
	www.research.ibm.com /topics/popups/deep/storage/html/ghow.html (265 words)

	math lessons - Tunnel magnetoresistance
		This is known as tunnel magnetoresistance (TMR) effect.
		It was discovered in 1975 by Julliere [1], using iron as the ferromagnet and germanium as the insulator.
		following renewed interest in this field fueled by the discovery of the giant magnetoresistive effect [3,4].
	www.mathdaily.com /lessons/Magnetic_tunnel_effect (127 words)

	(Anisotropic) Magnetoresistive (MR/AMR) Heads
		The newest type of technology commonly used in read/write heads is much more of a radical change to the way the read/write head works internally than the earlier advances, which were much more evolutionary and more related to how the head was made than how it worked.
		With GMR heads now on the market, there is the potential for confusion between the terms "magnetoresistive" and "giant magnetoresistive".
		The successor to MR now appears to be GMR heads, named for the giant magnetoresistive effect.
	www.storagereview.com /guide2000/ref/hdd/op/heads/techMR.html (745 words)

	Define giant magnetoresistive effect - a definition from Whatis.com
		GMR is the newest generation of hard disk drive storage.
		It provides almost three times the data density of its immediate predecessor, magnetoresistive head technology.
		The magnetic rotation yields a very large change in sensor resistance, which in turn provides a signal that can be picked up by the electric circuits in the drive.
	searchstorage.techtarget.com /sDefinition/0,,sid5_gci214472,00.html (313 words)

	Giant Magnetoresistive (GMR) Heads
		GMR heads are not named "giant" because of their size; they are actually smaller than the regular (A)MR heads developed by IBM many years earlier.
		Rather, they are named after the giant magnetoresistive effect, first discovered in the late 1980s by two European researchers, Peter Gruenberg and Albert Fert, who were working independently.
		A key advance was the discovery that the GMR effect would work on multilayers of materials deposited by sputtering, the same technique used to make thin film media and thin film read/write heads.
	www.pcguide.com /ref/hdd/op/heads/techGMR-c.html (933 words)

	Moore's law - Wikipedia, the free encyclopedia
		A similar law has held for hard disk storage cost per unit of information.
		The rate of progression in disk storage over the past decades has actually sped up more than once, corresponding to the utilization of error correcting codes, the magnetoresistive effect and the giant magnetoresistive effect.
		The current rate of increase in hard drive capacity is roughly similar to the rate of increase in transistor count and has been dubbed Kryder's law.
	en.wikipedia.org /wiki/Moores_Law (2312 words)

	The Giant Magnetoresistive Group (Site not responding. Last check: 2007-11-04)
		Recently, IBM has announced their record-breaking 16.8 gigabyte hard disk drive which is based on a new read-head design.
		The new design was possible due to a discovery in 1988 of a new phenomenon called the "giant magnetoresistive (GMR)" effect.
		The discovery was made by two scientists: Peter Gruenberg of KFA research center in Jülich, Germany, and Albert Fert of the University of Paris-Sud.
	www.coe.uncc.edu /~mhasan/gmr.html (289 words)

	IBM Research \| Press Resources \| IBM and Stanford Collaborate on World-class Spintronics Research
		Introduced in 1997, the giant magnetoresistive (GMR) head developed at the IBM Almaden lab, is a super-sensitive magnetic-field sensor that enabled a 40-fold increase in data density over the past seven years.
		The concept of electron spin was created and developed in the mid-1920s by Wolfgang Pauli and a number of European physicists.
		The late 1980s discoveries of the giant magnetoresistive (GMR) effect and oscillatory coupling in magnetic multilayers -- as well as the ability to make ultra-thin layers with precise control -- led to commercial products.
	domino.research.ibm.com /comm/pr.nsf/pages/news.20040426_spinaps.html (1126 words)

	Log in ....Tribune--Bits & Bytes
		The term is usually referred to in reference to GMR heads.
		GMR heads are not named ‘giant’ because of their size.
		The technology is named for the giant magnetoresistive effect, first discovered by two European researchers — Peter Gruenberg and Albert Fert — in the late 1980s.
	www.tribuneindia.com /2001/20010625/login/bits.htm (159 words)

	Magnetics Group: Magnetics Publications
		A. Kos, S. Russek, Y. Kim, and R. Cross, "High current density measurements of giant magnetoresistive spin-valves for magnetic recording and sensor applications," IEEE Transactions on Magnetics 33, 3541-3543 (1997).
		J. Oti and S. Russek, "Micromagnetic simulations of magnetoresistive behavior of sub-micrometer spin-valve MRAM devices," IEEE Transactions on Magnetics 33, 3298-3300 (1997).
		T. Crawford, C. Rogers, T. Silva, and Y. Kim, "Second-harmonic magneto-optic Kerr effect from spin-valve test structures: correlation with magnetoresistance response," IEEE Transactions on Magnetics 33, 3598-3600 (1997).
	www.boulder.nist.gov /div818/81803/htmls/magnetics_publications.html (6713 words)

	GMR: A Giant Leap for IBM Research
		The Giant Magnetoresistive Head: A giant leap for IBM Research
		But now, after intense and dedicated research and development, "giant magnetoresistance" -- or GMR for short -- makes its mass-market debut in IBM's record-breaking 16.8-gigabyte hard disk drive for desktop computers using a special GMR structure developed at IBM called a spin valve.
		Now we'd like to tell you how we envision its effect on your future.
	www.research.ibm.com /research/gmr.html (1157 words)

	EDevelopment of Eddy Current Meander Probe Array, 15-9067 (Site not responding. Last check: 2007-11-04)
		The line-current excitation from the meander coil and the use of an array of sensors allow flaws of all lengths to be detected and will ultimately allow realtime data imaging to provide rapid inspection and easy interpretation.
		Accomplishments - An ECT probe array consisting of a meander excitation coil and magnetic field sensors based on the giant magnetoresistive (GMR) effect was fabricated and tested.
		The eddy current array probe consists of meander excitation coil and giant magnetoresistive (GMR) effect sensors positioned in holes cut in the substrate between the meander coil conductors.
	www.swri.org /3pubs/IRD2000/15-9067.htm (380 words)

	Giant Magnetoresistive Effect (Site not responding. Last check: 2007-11-04)
		I suspect the GMR (giant magnetoresistive) effect may have some simple applications.
		Perhaps a GMR head salvaged from a defective hard drive could be adapted.
		Search on Google for "giant magnetoresistive" for lots of links.
	www.amrad.org /pipermail/tacos/2004/002855.html (159 words)

	TA: Article (Site not responding. Last check: 2007-11-04)
		This technology stems from the "giant magnetoresistive" (GMR) effect, in which an applied magnetic field changes certain materials' resistance to current flow.
		Seeing the potential for this effect to transform magnetic sensors, NVE developed novel GMR material and processing technology with funding from BMDO's SBIR program.
		GMR materials are ideal for BMDO space sensors because of their radiation hardness and ability to operate over a wide range of temperatures.
	www.mdatechnology.net /printerpage_article.asp?id=2105 (360 words)

	Sensors, Measurements and Instrumentation Links (Site not responding. Last check: 2007-11-04)
		Magnetoresistive sensors - sensitivity down to about 0.1 nT at low frequencies to 1 pT at high frequencies.
		Wiegand effect sensors - generate output pulses when alternating magnetic fields pass near the sensor - HID Corporation.
		Magnetotelluric (MT) sensing is a technique used for investigating the structure and composition of the earth's lithosphere (surface down to about 10 or even 100 km) for geophysics research and oil, gas, water or mineral exploration.
	www.sensors-research.com /links.htm (4054 words)

	Abstract (Site not responding. Last check: 2007-11-04)
		Magnetoresistive RAM (MRAM): A Technology for Computer Systems on a Single Chip
		This non-volatility is attractive not only to military and space applications, also to the commercial world if can be made reliable, dense, and cost-effective.
		Modern MRAM utilizes the giant magnetoresistive (GMR) effect in magnetic multilayer.
	www.cs.cmu.edu /~tcm/cs_seminars/zhu_abstract_f99.html (239 words)

	Spin Glass Behavior in Irradiated LSMO and LCMO Thin Films (Site not responding. Last check: 2007-11-04)
		Substitution of a di-valent cation for tri-valent La in LaMnO_3 has been shown to result in the observation of "colossal" magnetoresistance (CMR) in thin film samples.
		This effect differs from the giant magnetoresistive (GMR) effect seen in magnetic multilayers in that it is not an engineered effect, but rather a materials property.
		However, recent studies of ion-beam irradiated LCMO and LSMO thin films have provided strong evidence that CMR is a disorder-induced phenomenon.
	flux.aps.org /meetings/YR99/CENT99/abs/S7990007.html (216 words)

	GMR - Webopedia.com
		Short for giant magnetoresistive, a hard disk drive storage technology.
		This guide provides diagrams and a technical explanation of the technology.
		IBM's magnetoresistive and giant magnetoresistive head technologies enable data storage products with the industry's highest areal densities.
	itmanagement.webopedia.com /TERM/G/GMR.html (400 words)

	Safety device uses GMR sensor - 7/10/2003 - EDN (Site not responding. Last check: 2007-11-04)
		The proposed circuit uses a new method for differential current sensing (Figure 1).
		The method entails the use of Helmholtz coils and a magnetic sensor based on the GMR (giant-magnetoresistive) effect.
		Daugton, JM, "Giant magnetoresistive in narrow stripes, IEEE Transactions on Magnetics, 1992.
	www.edn.com /ednmag/article/CA307870.html?spacedesc=designideas (572 words)

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