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

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Next Issue

3 Jul 2006

Volume 89, Issue 1, Articles (01xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 89, 011901 (2006); http://dx.doi.org/10.1063/1.2218670 (3 pages)

L. S. Wang, S. Tripathy, B. Z. Wang, J. H. Teng, S. Y. Chow, and S. J. Chua
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Search for ferromagnetism in conductive Nb:SrTiO3 with magnetic transition element (Cr, Co, Fe, Mn) dopants

S. X. Zhang, S. B. Ogale, Darshan C. Kundaliya, L. F. Fu, N. D. Browning, S. Dhar, W. Ramadan, J. S. Higgins, R. L. Greene, and T. Venkatesan

Appl. Phys. Lett. 89, 012501 (2006); http://dx.doi.org/10.1063/1.2219145 (3 pages) | Cited 10 times

Online Publication Date: 5 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Thin films of (0.5%, 1%) Nb:SrTiO3 dilutely doped with (2 at. %) magnetic transition elements (Cr, Co, Fe, Mn) are examined for ferromagnetism. X-ray diffraction, Rutherford backscattering ion channeling, scanning transmission electron microscopy Z-contrast imaging, and electron energy loss spectroscopy techniques establish high crystalline quality of the films with no impurity phase(s) and highly uniform dopant distribution. Although the film conductivity improves dramatically by Nb doping, no ferromagnetism is found in any of our samples over the temperature range of 365 down to 5 K. This is contrasted to the case of ferromagnetism reported in cobalt doped (La,Sr)TiO3.
Show PACS
75.70.Ak Magnetic properties of monolayers and thin films
75.50.Pp Magnetic semiconductors
75.50.Dd Nonmetallic ferromagnetic materials
75.30.Hx Magnetic impurity interactions
68.37.Lp Transmission electron microscopy (TEM)

Inverted spin polarization of Heusler alloys for spintronic devices

Andy Thomas, Dirk Meyners, Daniel Ebke, Ning-Ning Liu, Marc D. Sacher, Jan Schmalhorst, Günter Reiss, Hubert Ebert, and Andreas Hütten

Appl. Phys. Lett. 89, 012502 (2006); http://dx.doi.org/10.1063/1.2219333 (3 pages) | Cited 14 times

Online Publication Date: 6 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A magnetic logic concept overcomes the major limitations of field programmable gate arrays while having a 50% smaller unit cell than conventional designs utilizing magnetic tunnel junctions with one Heusler alloy electrode. These show positive and negative tunneling magnetoresistance values at different bias voltages at room temperature which generally add an additional degree of freedom to all spintronic devices.
Show PACS
85.75.-d Magnetoelectronics; spintronics: devices exploiting spin polarized transport or integrated magnetic fields
85.70.Kh Magnetic thin film devices: magnetic heads (magnetoresistive, inductive, etc.); domain-motion devices, etc.
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
72.25.Mk Spin transport through interfaces

Minute doping with deleterious rare earths in YBa2Cu3O7−δ films for flux pinning enhancements

P. N. Barnes, J. W. Kell, B. C. Harrison, T. J. Haugan, C. V. Varanasi, M. Rane, and F. Ramos

Appl. Phys. Lett. 89, 012503 (2006); http://dx.doi.org/10.1063/1.2219391 (3 pages) | Cited 13 times

Online Publication Date: 6 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
To enhance the critical current density of YBa2Cu3O7−δ films, flux pinning centers are intentionally added to inhibit flux flow in applied magnetic fields. Here we provide an initial demonstration that the incorporation of very minor additions ( ⩽ 1% of Y as opposed to the 10%–40% in standard substitutions) of typically deleterious rare earths into high quality YBa2Cu3O7−δ thin films provides significant improvement of the film’s in-field current density. This is accomplished without reoptimization of the deposition parameters. Instead of site substitution for Y as might be expected, the deleterious rare earths potentially result in the formation of nanoparticulates.
Show PACS
74.78.-w Superconducting films and low-dimensional structures
74.72.-h Cuprate superconductors
61.72.up Other materials
74.25.Uv Vortex phases (includes vortex lattices, vortex liquids, and vortex glasses)
74.25.Sv Critical currents

Mn L3,2 x-ray absorption and magnetic circular dichroism in ferromagnetic Ga1−xMnxP

P. R. Stone, M. A. Scarpulla, R. Farshchi, I. D. Sharp, E. E. Haller, O. D. Dubon, K. M. Yu, J. W. Beeman, E. Arenholz, J. D. Denlinger, and H. Ohldag

Appl. Phys. Lett. 89, 012504 (2006); http://dx.doi.org/10.1063/1.2219713 (3 pages) | Cited 12 times

Online Publication Date: 7 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have measured the x-ray absorption and x-ray magnetic circular dichroism (XMCD) at the Mn L3,2 edges in ferromagnetic Ga1−xMnxP films for 0.018 ⩽ x ⩽ 0.042. Large XMCD asymmetries at the L3 edge indicate significant spin polarization of the density of states at the Fermi energy. The temperature dependence of the XMCD and moment per Mn of 2.67±0.45μB calculated using sum rules are consistent with magnetometry values. The spectral shapes of the x-ray absorption and XMCD are nearly identical with those for Ga1−xMnxAs indicating that the hybridization of Mn d states and anion p states is similar in the two materials.
Show PACS
78.70.Dm X-ray absorption spectra
78.20.Ls Magneto-optical effects
75.50.Pp Magnetic semiconductors
75.50.Dd Nonmetallic ferromagnetic materials
75.30.Cr Saturation moments and magnetic susceptibilities
75.70.Ak Magnetic properties of monolayers and thin films

Diffusion and clustering of substitutional Mn in (Ga,Mn)As

Hannes Raebiger, Maria Ganchenkova, and Juhani von Boehm

Appl. Phys. Lett. 89, 012505 (2006); http://dx.doi.org/10.1063/1.2219337 (3 pages) | Cited 12 times

Online Publication Date: 7 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The Ga vacancy mediated microstructure evolution of (Ga,Mn)As during growth and postgrowth annealing is studied using a multiscale approach. The migration barriers for the Ga vacancies and substitutional Mn together with their interactions are calculated using first principles, and temporal evolution at temperatures 200–350 °C is studied using lattice kinetic Monte Carlo simulations. We show that at the typical growth and annealing temperatures (i) Ga vacancies provide an efficient diffusion transport for Mn and (ii) in 10–20 h the diffusion of Mn promotes the formation of clusters. Clustering reduces the Curie temperature, and explains its decrease during long-term annealing.
Show PACS
66.30.J- Diffusion of impurities
66.30.Lw Diffusion of other defects
61.72.J- Point defects and defect clusters
61.72.Cc Kinetics of defect formation and annealing

Multifilament YBa2Cu3O6+x-coated conductors with minimized coupling losses

G. A. Levin, P. N. Barnes, J. W. Kell, N. Amemiya, Z. Jiang, K. Yoda, and F. Kimura

Appl. Phys. Lett. 89, 012506 (2006); http://dx.doi.org/10.1063/1.2219393 (3 pages) | Cited 9 times

Online Publication Date: 7 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report an experimental approach to making multifilament coated conductors with low losses in applied time-varying magnetic field. Previously, the multifilament conductors obtained for that purpose by laser ablation suffered from high coupling losses. Here we report how this problem can be solved. When the substrate metal in the grooves segregating the filaments is exposed to oxygen, it forms high resistivity oxides that electrically insulate the stripes from each other and from the substrate. As the result, the coupling loss has become negligible over the entire range of tested parameters (magnetic field amplitudes B and frequencies f).
Show PACS
74.72.-h Cuprate superconductors
81.65.-b Surface treatments
81.40.Gh Other heat and thermomechanical treatments
42.62.-b Laser applications

Magnetic anisotropy of Ga1−xMnxAs thin films on GaAs (311)A probed by ferromagnetic resonance

C. Bihler, H. Huebl, M. S. Brandt, S. T. B. Goennenwein, M. Reinwald, U. Wurstbauer, M. Döppe, D. Weiss, and W. Wegscheider

Appl. Phys. Lett. 89, 012507 (2006); http://dx.doi.org/10.1063/1.2219408 (3 pages) | Cited 14 times

Online Publication Date: 7 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have studied the magnetic anisotropy of Ga1−xMnxAs thin films grown by low-temperature molecular beam epitaxy on GaAs (311)A substrates by means of ferromagnetic resonance spectroscopy. The angular dependence of the ferromagnetic resonance fields observed can be explained by two main contributions to the magnetic anisotropy: a cubic magnetic anisotropy field oriented along the crystallographic ⟨001⟩ axes caused by the symmetry of the GaAs host lattice, and an effective uniaxial magnetic anisotropy field along [311] presumably caused by the homoepitaxial growth of the layer. Additional smaller magnetic anisotropy contributions are discussed. Consequently, the dominating magnetic anisotropy of Ga1−xMnxAs on GaAs (311)A substrate appears to have the same origin as on GaAs (100) substrate.
Show PACS
75.50.Pp Magnetic semiconductors
75.50.Dd Nonmetallic ferromagnetic materials
75.70.Ak Magnetic properties of monolayers and thin films
75.30.Gw Magnetic anisotropy
76.50.+g Ferromagnetic, antiferromagnetic, and ferrimagnetic resonances; spin-wave resonance

Ferromagnetism in Fe-implanted a-plane ZnO films

P. Wu, G. Saraf, Y. Lu, D. H. Hill, R. Gateau, L. Wielunski, R. A. Bartynski, D. A. Arena, J. Dvorak, A. Moodenbaugh, T. Siegrist, J. A. Raley, and Yung Kee Yeo

Appl. Phys. Lett. 89, 012508 (2006); http://dx.doi.org/10.1063/1.2213519 (3 pages) | Cited 21 times

Online Publication Date: 7 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Fe ions of dose 5×1016 cm−2 were implanted at 200 keV into a-plane ZnO epitaxial films. The epitaxial quality of the postannealed samples was verified by x-ray diffraction ω-rocking curves and φ scans, whereas x-ray absorption spectroscopy identified the presence of both Fe2+ and Fe3+ ions, as well as changes in their relative concentration during postannealing. Superconducting quantum interference device measurements show that the as-implanted and postannealed films are ferromagnetic at room temperature. The saturation magnetization reduces during annealing possibly due to the decrease in the number of oxygen vacancies.
Show PACS
75.50.Pp Magnetic semiconductors
75.50.Dd Nonmetallic ferromagnetic materials
61.72.up Other materials
61.72.Cc Kinetics of defect formation and annealing
78.70.Dm X-ray absorption spectra
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close