ultrathin magnetic structures iv. applications of nanomagnetism, 2005, p.269

[...]... understanding of the reciprocal effect, current induced magnetic reversal, in which the electron current induces a reversal of the magnetisation in magnetic nanostructures This phenomenon would allow magnetic switching in nanoscale devices by all electrical means without the need to apply external magnetic fields In the earlier two volumes, UMS (Ultrathin Magnetic Structures) I and II, we described many of the... computation were often at variance As computational techniques and efficiency have rapidly evolved in the last few years guided by the increasing availability of high quality magnetic images on well defined nanostructures, the possibility of accurately predicting the micromagnetic states of magnetic nanostructures has become a reality In Chap 5 Arrott introduces the subject of micromagnetics and the... intelligent design of the elements themselves 10 G.A Prinz can have a large impact on the latitude of control needed in those steps The switching behavior of one element is determined by the properties of its constituent films themselves (coercivity and anisotropy), the micromagnetic behavior of the element (determined by its shape), the magnetic coupling of the individual components of an element to... toroids, for the same thickness of the permalloy soft layer, stabilizes the magnetic orientation against thermal upset at 125 ◦ C down to a dimension of l = 0.01 µm [2.29], which implies a terminal density of 60 · 109 cm2 Thus, the vertical GMR sense line architecture offers the highest ultimate density of all the approaches, 200 times that of in-plane GMR and 100 times that of MTJ, once lithography tools... stored in a soft magnetic layer immediately above it The magnetic layer is patterned into a longitudinal element, whose one end is centered at the intersection of the Hall cross The fringing field, from the end poles, passes through the plane of the cross generating a Hall voltage when current is passed through the device Reversing the magnetization of the magnetic element, reverses the sign of the fringing... for hybrid metal devices A crucial aspect of nanoscale magnetic devices is the requirement to control the spin configura- 1 Introduction 3 tions with the structure so that the magnetic switching and stable magnetic states can be optimised for such applications as magnetic memory elements in MRAM arrays The initial magnetic states and switching processes are, of course, intimately linked and both are... study of electrical transport in magnetic materials was confined to a very small community of researchers Now, slightly more than a decade later, it has become one of the dominant themes of condensed matter physics and materials science involving thousands of scientists, worldwide This is driven both by the fact that the subject of spin-polarized transport is an interesting and challenging field of study,... switching the magnetization of the quantum well Some degree of success has been realized in each of the devices described above However, more significant progress towards a practical device has been thwarted by the lack of one or more of the components essential to the intended operation Fig 3.1 Schematic diagrams of a number of semiconductor spintronic device concepts: (a) the spin-FET of reference [3.8],... publication of volumes I and II in this series 10 years ago, there has been an explosion of interest and activity in the subject of thin film magnetism Much of this activity has been stimulated by the use of giant magnetoresistance read heads in hard disc drives and by the continuing advances in storage densities achievable in thin film media Such applications are now almost as familiar as those of the semiconductor... focus of the present volumes In volume III, the first of the two new volumes, we presented further advances in the fundamental understanding of thin film magnetic properties and of methods for characterising thin film structure which underpin the present spintronics revolution Here in volume IV we deal with the fundamentals of spintronics: magnetoelectronic materials, spin injection and detection, micromagnetics . unique properties of interfaces of VI Preface ultrathin films structures were already in place, but applications were only a promise and the ‘engineering’ of new magnetic materials using nanostructures. data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright L aw of September 9, 1965, in its current version, and permission for.