Applications of spin dependent transport materials

Abstract

Newly developed materials that exhibit large changes in effective resistance with applied fields are being put to practical use. Magnetic multilayers with giant magnetoresistance (GMR) and spin dependent tunnelling (SDT) structures are being used in magnetic field sensors. Spin valves are being sold in read heads for hard drives and galvanic isolators. Both spin valves and SDT structures are being used in non-volatile random access memory development. After a brief introduction to these materials, the development of their uses in sensors, read heads, isolators and non-volatile memory are summarized. GMR magnetic field sensors represent a small, but growing market. SDT sensors have the potential to sense very small fields (to 1 pT). Spin valve read heads have enabled very high aerial packing densities for hard drives, up to 24 Gbits per square inch. GMR isolators can be used to duplicate the function of opto-isolators, but at much higher speeds and packing densities. Application of these materials to non-volatile random access memory could result in speeds and densities of semiconductor memory with the non-volatility of hard disk drives. Future directions in this field indicate a merging of semiconductor and these new magnetic materials.

Spintronics: Fundamentals and applications

“…8 The Zeeman-3 Reviews on emerging applications include those of Das Sarma et al (2000a, 2000c); Wolf and Treger (2000); ; Wolf et al (2001); Oestreich et al (2002); Rashba (2002c);Ž utić (2002a. 4 Established schemes and materials are reviewed by Tedrow and Meservey (1994); Prinz (1995Prinz ( , 1998; Gijs and Bauer (1997); Gregg et al (1997); Ansermet (1998); Bass and Pratt, Jr. (1999); Daughton et al (1999); Stiles (2004). 5 See, for example, the books of Hartman (2000); Ziese and Thornton (2001); Hirota et al (2002); Levy and Mertig (2002); Maekawa et al (2002); Parkin (2002); Shinjo (2002);and Chtchelkanova et al (2003).…”

Magnetic antidot to dot crossover in Co and Py nanopatterned thin films

“…The control of the magnetic properties of ferromagnetic thin films is an important topic for both the fundamental understanding of low-dimensional magnetism and a broad range of applications, such as magnetic recording media [1], sensors [2], and magnonic devices [3,4]. A strong dependence of the magnetization reversal mechanisms on the microstructure and the presence of defects makes magnetic properties hardly controllable.…”

Vortex core size in interacting cylindrical nanodot arrays

“…[9] In particular, two-dimensional arrays of magnetic nanoparticles have been proposed as candidates for magnetoresistive random access memory (MRAM) devices. [10,11,12] Recent studies on such structures have been carried out with the aim of determining the stable magnetized state as a function of the geometry of the particles. [3,4,13,14,15,16] In the case of cylindrical particles, three idealized characteristic configurations have been identified: ferromagnetic with the magnetization parallel to the basis of the cylinder, ferromagnetic with the magnetization parallel to the cylinder axis, and a vortex state in which most of the magnetic moments lie parallel to the basis of the cylinder.…”