Spintronic properties

The creation of nanoscale sandwiches of compound semiconductor heterostructures, with gradients of chemical composition that are precisely sculpted, could produce quantum wells with appropriate properties. One can eventually think of a combined device that incorporates logic, storage, and communication for computing—based on a combination of electronic, spintronic, photonic, and optical technologies. Precise production and integrated use of many different materials will be a hallmark of future advanced device technology. 

Although TDDFT is considered to be a well-established tool for the investigation of dynamical properties of molecular systems, development of better and more accurate XC functionals of density and current density is still an ongoing process. Spin polarization has been neglected in the present discussion, which is, however, important particularly in view of the many recent developments in the areas of magnetism and spintronics. While only a few chosen aspects have been covered in this chapter to provide a glimpse of the basic formalism, there have been many new developments in this exciting area of research in recent years. 

Fig. I. Concept of spin-electronics (spintronics). In semiconductor spin-electronics spin properties as well as electronic and optical properties are utilized al the same time.

It is also possible to prepare V205-based vanadium nanotubes from surfactant solution. They are formed using oxotriisopropoxovanadium(V) and have been found to have unique electronic properties that can be controlled by electron doping [5], In fact, these tubes offer the possibility of spin control and, therefore, have significant potential in the development of spintronic devices. 

The present study has illustrated the subtle interplay between geometric properties such as film thickness and the spin structure in magnetic trilayers. We hope that our results will lead to a deeper understanding of magnetic heterostructures and will help to design and improve future spintronic devices. 

Fullerenes and their chemical compounds are perspective materials for application in nanotechnology, spintronics and single-electronics [1], Thus, the search of ways of high-speed, contactless, selective control of electron-optical properties of fullerene-based materials is actual problem. It is well known, that weak magnetic field (MF) with induction B < IT effectively influences electron-optical properties of some organic compounds (for instance, anthracene, tetracene, etc.) [2]. 

Finally, with the aim of industrial applications, assembling the magnetic molecules onto various substrates is another important field, but one that has been less studied. The application potential of magnetic molecular materials in the manufacture of molecular based memory devices, quantum computing, and spintronics devices, requires an understanding of the interactions between the material and substrate in order to manipulate the spin and electronic states of the target system to realize the desired specific properties [137]. 

Zinc oxide (ZnO, wurtzite structure) eliminates oxygen on heating to form nonstoichio-metric colored phases, Zni+xO with x < 70 ppm. ZnO is almost transparent and is used as white pigment, polymer stabilizer, emollient in zinc ointments, creams and lotions, as well as in the production of Zu2Si04 for TV screens. A major application is in the rubber industry to lower the temperatures and to raise the rate of vulcanization. Furthermore, it is an n-type semiconductor (band gap 3.37 eV) and shows piezoelectric properties, making zinc oxide useful for microsensor devices and micromachined actuators. Other applications include gas sensors , solar cell windows and surface acoustic devices. ZnO has also been considered for spintronic application because of theoretical predictions of room-temperature ferromagnetism . 

Last years diluted ternary semiconductors A°B C 2 which may possess magnetic and semiconducting properties at the same time became the issue of great interest due to their potential application in spintronic devices [1-4]. Meanwhile the systematic representation of changes in their properties upon doping with different elements is still to be made. 

One such quantum property of the electron is its spin, i.e., its magnetism. Devices that rely on an electron s spin to perform their functions form the foundation of spintronics (short for spin-based electronics), also defined as magneto-electronics. Information-processing teclmology has thus far relied on purely charge-based devices, ranging from the now outdated vacuum tube to today s million-transistor microchips. The conventional electronic... 

To date, a relatively small number of materials have been explored in a molecular spintronics device and much remains to be understood. For example, the couphng between the molecular layer and the magnetic electrodes is believed to play a very significant role due to the discrete nature of the molecule s HOMO and LUMO, in contrast to the band properties inherent in a continuous-lattice material. The energies of the frontier orbitals with respect to the Fermi level of the electrodes, the broadening of the frontier orbitals into (narrow) bands and the orientation-dependent orbital overlap between molecule and electrode will all contribute to the transport of spins across the interface. Study of the magnetic properties of molecule surface systems is, therefore, highly important and may also lead to new types of spintronic devices. 

In more recent times, the field has increasingly focused on topics where molecular materials have an advantage over continuous-lattice solids. Such studies can exploit the modular synthesis of molecular materials, whereby different molecules with differing functions can be combined to form a hybrid material with interacting magnetic and/or conducting and/ or optical properties. This is leading to new fields such as molecular spintronics, multifunctional and switchable materials where... 

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