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Ferromagnetic Semiconductor (ferromagnetic + semiconductor)

Distribution by Scientific Domains

Physics and Astronomy	80%

Selected Abstracts

Direct Laser Writing of Nanoscale Light-Emitting Diodes

ADVANCED MATERIALS, Issue 29 2010
Oleg Makarovsky
Nanoscale light-emitting diodes (nanoLEDs) and arrays of nanoLEDs produced by laser controlled diffusion of interstitial manganese (Mni) donor ions out of the ferromagnetic semiconductor (GaMn)As towards the underlying layers of a quantum well heterostructure. The approach represents an alternative to deep etching for the creation of nanoscale current channels and nanoLEDs. [source]

Microcircuit tailoring in ferromagnetic semiconductor (Ga,Mn)As

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 1 2003
T. Figielski
Abstract In order to search for novel giant-magnetoresistance systems, we fabricated and investigated narrow constrictions in the layers of the ferromagnetic semiconductor (Ga,Mn)As. We found that constrictions a few hundred nanometers wide, tailored by means of the electron-beam lithography and wet etching, were not conducting at liquid helium temperatures unless illuminated, probably due to the trapping action of surface states appearing on an extra surface area denuded by the etching. To avoid this, we used selective implantation of oxygen ions into the ferromagnetic layer to tailor the constrictions. We have shown that such an implantation inactivates Mn acceptors in the layer and destroys ferromagnetism. We propose an application of oxygen ion implantation as a method of fabricating microcircuits in future spin electronics based on Mn-containing III,V semiconductor compounds. [source]

Magnetic semiconductors in ternary Cd,Mn,Te compounds

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 5 2008
Yong Liu
Abstract Since Mn-doped CdTe in zincblende structure has been fabricated for Mn concentrations from 0 to 0.5, we use a first-principles full-potential method to study CdTe-based ternary Cd,Mn,Te compounds for possible magnetic semiconductors. The compounds are constructed by substituting Mn for some Cd atoms in zincblende CdTe. We optimize fully their geometric structures and internal atomic positions, and then study their electronic and magnetic properties. We find that the stable CdMnTe2 and Cd3MnTe4 are antiferromagnetic semiconductors with space groups 160 and 111, and the stable Cd7MnTe8 is a layered ferromagnetic semiconductor with space group 115. Their real lattice constants are a little smaller than CdTe's and an Mn atom contributes 5 Bohr magnetons to their total magnetic moments. The antiferromagnetism for the CdMnTe2 is attributed to the Te-based superexchange of Mn spins. For the other two, the MnMn spin interactions are dependent on the MnMn distance and the environment. The antiferromagnetism for the Cd3MnTe4 and the layered ferromagnetism for the Cd7MnTe8 can be attributed to two weaker indirect exchange interactions based on both Cd and Te. The Kohn,Sham gaps of the three magnetic semiconductors are 0.52 eV, 0.80 eV, and 1.23 eV, respectively. The real semiconductor gaps may be larger than 1 eV considering the fact that the Kohn,Sham gap of CdTe is 0.55 eV but the experimental semiconductor gap is 1.56 eV at 300 K. These magnetic semiconductors, compatible with semiconductors such as CdTe, could be useful in spintronics applications. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Nitrides as spintronic materials

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 2 2003
Tomasz Dietl
The Guest Editors of the Proceedings of the 5th International Conference on Nitride Semiconductors (ICNS-5), Hiroshi Amano and Takashi Udagawa, have nominated the invited presentation by Tomasz Dietl [1] as Editor's Choice of the present issue of physica status solidi (b). This paper is a progress report on spintronics-related issues in Mn-based III-nitrides as potential diluted magnetic semiconductors. The cover picture shows the computed values of the Curie temperature for various p-type III,V compounds containing 5% of Mn in the S = 5/2 high spin state and 3.5 × 1020 holes per cm3, predicting that TC should exceed room temperature in the Mn-based nitrides. Thomas Dietl is head of the Low-Temperature Physics Group and professor at the Institute of Physics of the Polish Academy of Sciences. He is one of the most experienced researchers in the area of ferromagnetic semiconductors, spin-related phenomena and other current topics of semiconductor physics with many publications and invited talks at conferences and seminars world-wide. The full Proceedings of the 5th International Conference on Nitride Semiconductors (ICNS-5) are published in physica status solidi (c) , conferences and critical reviews, Vol. 0, No. 7 (November 2003) (ISBN 3-527-40489-9). Conference papers can also be found in phys. stat. sol. (a) 200, No. 1 (2003). [source]