Advances in nanoscale magnetism

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Intensive investigations on nanoscale magnetism have promoted remarkable progressintechnologicalapplicationsofmagnetisminvariousareas.Thete- nical progress of recent years in the preparations of multilayer thin ?lms and nanowires led to the discovery of Giant Magnetoresistance (GMR), imp- ing an extraordinary change in the resistivity of the material by varying the applied external magnetic ?eld. The Nobel Prize for Physics in 2007 was awardedtoAlbertFertandPeterGrun ] bergfortheirdiscoveryofGMR.App- cations of this phenomenon have revolutionizedtechniques for retrieving data fromharddisks.Thediscoveryalsoplaysamajorroleinvariousmagnetics- sors as well as the development of a new generation of electronics. The use of GMRcanberegardedasoneofthe?rstmajorapplicationsofnanotechnology. The GMR materials have already found applications as sensors of low magnetic ?eld, a key component of computer hard disk heads, magnetores- tive RAM chips etc. The "read" heads for magnetic hard disk drives have allowed us to increase the storage density on a disk drive from 1 to 20 Gbit per square inch, merely by the incorporation of the new GMR materials. On the other hand, recently discovered giant magneto-impedance (GMI) mate- als look very promising in the development of a new generation of microwave band electronic devices (such as switches, attenuators, and antennas) which could be managed electrically.