APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

29 Sep 2008

Volume 93, Issue 13, Articles (13xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 93, 132101 (2008); http://dx.doi.org/10.1063/1.2988720 (3 pages)

Yueh-Nan Chen and Lukas Gilz
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Room temperature ferromagnetism in Mn-doped CdS nanorods

Savas Delikanli, Shuli He, Yueling Qin, Peihong Zhang, Hao Zeng, Hongwang Zhang, and Mark Swihart

Appl. Phys. Lett. 93, 132501 (2008); http://dx.doi.org/10.1063/1.2982583 (3 pages) | Cited 13 times

Online Publication Date: 2 October 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Mn-doped CdS nanorods synthesized by solution phase chemistry demonstrate robust ferromagnetic properties at and above room temperature. The nanorods show large coercivity, possibly originating from the shape anisotropy. The hysteresis measurements reveal strong temperature dependence. Possible origin of the ferromagnetism is discussed.
Show PACS
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
75.50.Pp Magnetic semiconductors
81.16.-c Methods of micro- and nanofabrication and processing
81.07.-b Nanoscale materials and structures: fabrication and characterization
75.30.Gw Magnetic anisotropy
75.50.Tt Fine-particle systems; nanocrystalline materials

Atomic-scale chemical analyses of niobium oxide/niobium interfaces via atom-probe tomography

Kevin E. Yoon, David N. Seidman, Claire Antoine, and Pierre Bauer

Appl. Phys. Lett. 93, 132502 (2008); http://dx.doi.org/10.1063/1.2987483 (3 pages) | Cited 9 times

Online Publication Date: 2 October 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Niobium is the metal of choice for superconducting radio-frequency cavities for the future International Linear Collider. We present the results of atomic-scale characterization of the oxidation of niobium utilizing local-electrode atom-probe tomography employing picosecond laser pulsing. Laser pulsing is utilized to prevent a tip from fracturing as a buried niobium oxide/niobium interface is dissected on an atom-by-atom basis. The thickness of niobium oxide is about 15 nm, the root-mean-square chemical roughness is 0.4 nm, and the composition is close to Nb2O5, which is an insulator, with an interstitial oxygen concentration profile in Nb extending to a depth of 12 nm.
Show PACS
68.35.Ct Interface structure and roughness
81.65.Mq Oxidation
61.72.jj Interstitials

Selective domain wall depinning by localized Oersted fields and Joule heating

Dennis Ilgaz, Mathias Kläui, Lutz Heyne, Olivier Boulle, Fabian Zinser, Stephen Krzyk, Mikhail Fonin, Ulrich Rüdiger, Dirk Backes, and Laura J. Heyderman

Appl. Phys. Lett. 93, 132503 (2008); http://dx.doi.org/10.1063/1.2990629 (3 pages) | Cited 7 times

Online Publication Date: 2 October 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Using low temperature magnetoresistance measurements, the possibility to selectively move a domain wall locally by applying current pulses through a Au nanowire adjacent to a permalloy element is studied. We find that the domain wall depinning field is drastically modified with increasing current density due to the Joule heating and the Oersted field of the current, and controlled motion due to the Oersted field without any externally applied fields is achieved. By placing the domain wall at various distances from the Au wire, we determine the range of the Joule heating and the Oersted field and both effects can be separated.
Show PACS
75.60.Ch Domain walls and domain structure
72.15.Gd Galvanomagnetic and other magnetotransport effects
72.15.Jf Thermoelectric and thermomagnetic effects

Current-perpendicular-to-plane transport properties of polycrystalline Fe3O4/α-Fe2O3 heterostructures

W. B. Mi, E. Y. Jiang, and H. L. Bai

Appl. Phys. Lett. 93, 132504 (2008); http://dx.doi.org/10.1063/1.2993223 (3 pages) | Cited 2 times

Online Publication Date: 2 October 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Current-perpendicular-to-plane transport properties of sputtered polycrystalline Fe3O4/α-Fe2O3 heterostructures were investigated. A rectifying behavior was observed. The voltage shift increases linearly with temperature and turns from negative to positive at 230 K. The current-dependent magnetoresistance (MR) changes from negative to positive in the temperature range of 230–260 K. The largest negative MR is −32% at 230 K, and the positive MR at 305 K reaches 80% at 1.0 mA. The characteristic MR is thought to be caused by the rectifying effect and band structure at the Fe3O4/α-Fe2O3 interface.
Show PACS
73.40.Ei Rectification
75.50.Gg Ferrimagnetics
75.20.Ck Nonmetals
72.25.Mk Spin transport through interfaces

Observation of a high negative spin polarization at the Fe/MgO(100) surface oxidized at room temperature

M. Kurahashi, X. Sun, S. Entani, and Y. Yamauchi

Appl. Phys. Lett. 93, 132505 (2008); http://dx.doi.org/10.1063/1.2995995 (3 pages) | Cited 6 times

Online Publication Date: 2 October 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Spin polarization of an Fe/MgO(100) surface oxidized at room temperature has been analyzed with a spin-polarized metastable helium beam, which is an extremely surface sensitive spin probe, under high magnetic fields (0–50 kOe). The spin polarization of the Fe surface, although it initially decays with oxygen exposure, increases at >20 L (1 L = 10−6 Torr sec) and becomes comparable to that observed for a clean Fe surface at >100 L. The polarization is negative and especially high at around the Fermi level. This may be understood if we assume the formation of Fe3O4.
Show PACS
72.25.Mk Spin transport through interfaces
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
72.25.Ba Spin polarized transport in metals
75.50.Bb Fe and its alloys

Ferromagnetism induced by defect complex in Co-doped ZnO

En-Zuo Liu, Yan He, and J. Z. Jiang

Appl. Phys. Lett. 93, 132506 (2008); http://dx.doi.org/10.1063/1.2995997 (3 pages) | Cited 21 times

Online Publication Date: 2 October 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The effect of Al donor and O vacancy (VO) on the magnetic properties of Co-doped ZnO has been studied by first-principles calculations. It is found that only Al donor cannot induce ferromagnetism (FM) in Co-doped ZnO but can provide additional electrons, which results in the enhancement of Fermi level. The presence of VO makes the Co empty 3d-t2g minority state broadened, and a t2g-VO hybrid level at the conduction band minimum forms. The combination of Al donor and VO results in a charge transfer to the Co empty 3d-t2g minority states, which induces a strong carrier-mediated FM interaction. Our results give an explanation for the controversial magnetic properties of (Co, Al)-codoped ZnO reported in the literature.
Show PACS
71.20.Nr Semiconductor compounds
61.72.jd Vacancies
71.15.-m Methods of electronic structure calculations
75.50.Pp Magnetic semiconductors
75.50.Dd Nonmetallic ferromagnetic materials

On the possibility of ferromagnetism in carbon-doped anatase TiO2

Kesong Yang, Ying Dai, Baibiao Huang, and Myung-Hwan Whangbo

Appl. Phys. Lett. 93, 132507 (2008); http://dx.doi.org/10.1063/1.2996024 (3 pages) | Cited 47 times

Online Publication Date: 2 October 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
To see if ferromagnetism can occur in C-doped anatase TiO2, we performed first-principles calculations for a number of C-doped structures in which C atoms substitute O atoms. Our study shows that each C has spin-polarized 2p states in the band gap generating a magnetic moment of 2.0μB. The magnetic coupling between doped C atoms is substantial leading to either antiferromagnetism or ferromagnetism when the C⋯C distance lies between 3–4 Å. A strong ferromagnetic coupling occurs when the two C atoms form a slightly bent C–Ti–C unit by replacing two oxygen atoms at the opposite vertices of a TiO6 octahedron.
Show PACS
75.30.Cr Saturation moments and magnetic susceptibilities
75.50.Cc Other ferromagnetic metals and alloys
75.50.Pp Magnetic semiconductors
71.15.-m Methods of electronic structure calculations
71.20.Nr Semiconductor compounds

Fast computation of magnetostatic fields by nonuniform fast Fourier transforms

Evaggelos Kritsikis, Jean-Christophe Toussaint, Olivier Fruchart, Helga Szambolics, and Liliana Buda-Prejbeanu

Appl. Phys. Lett. 93, 132508 (2008); http://dx.doi.org/10.1063/1.2995850 (3 pages) | Cited 1 time

Online Publication Date: 3 October 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The bottleneck of micromagnetic simulations is the computation of the long-ranged magnetostatic fields. This can be tackled on regular N-node grids with fast Fourier transforms in time N log N, whereas the geometrically more versatile finite element methods (FEMs) are bounded to N4/3 in the best case. We report the implementation of a nonuniform fast Fourier transform algorithm, which brings a N log N convergence to FEM, with no loss of accuracy in the results.
Show PACS
75.40.Mg Numerical simulation studies
41.20.Gz Magnetostatics; magnetic shielding, magnetic induction, boundary-value problems
02.30.Uu Integral transforms
02.70.Dh Finite-element and Galerkin methods
02.60.Lj Ordinary and partial differential equations; boundary value problems
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close