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 Mar 2004

Volume 84, Issue 13, pp. 2223-2459

Issue Cover Spotlight Figure

Appl. Phys. Lett. 84, 2244 (2004); http://dx.doi.org/10.1063/1.1690471 (3 pages)

David R. Smith, David Schurig, Jack J. Mock, Pavel Kolinko, and Patrick Rye
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Modification of critical current density of MgB2 films irradiated with 200 MeV Ag ions

S. R. Shinde, S. B. Ogale, J. Higgins, R. J. Choudhary, V. N. Kulkarni, T. Venkatesan, H. Zheng, R. Ramesh, A. V. Pogrebnyakov, S. Y. Xu, Qi Li, X. X. Xi, J. M. Redwing, and D. Kanjilal

Appl. Phys. Lett. 84, 2352 (2004); http://dx.doi.org/10.1063/1.1687982 (3 pages) | Cited 21 times

Online Publication Date: 23 March 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The effect of 200 MeV Ag ion irradiation on the temperature and field dependence of critical current density (JC) of high quality MgB2 thin films is studied. Substantial increase in JC is observed over a certain field range for the film irradiated at a dose of 1012 ions/cm2. Our analysis suggests that columnar defects are not formed under irradiation conditions used in these studies, which correspond to an electronic energy loss of about 16 keV/nm. Defects clusters are likely to be responsible for the observed improvement in JC.© 2004 American Institute of Physics.
Show PACS
74.25.Sv Critical currents
61.80.Jh Ion radiation effects
61.72.-y Defects and impurities in crystals; microstructure
74.78.-w Superconducting films and low-dimensional structures

Magneto-optical properties of a highly transparent cadmium ferrite-based magnetic fluid

A. F. Bakuzis, K. Skeff Neto, P. P. Gravina, L. C. Figueiredo, P. C. Morais, L. P. Silva, R. B. Azevedo, and O. Silva

Appl. Phys. Lett. 84, 2355 (2004); http://dx.doi.org/10.1063/1.1690497 (3 pages) | Cited 28 times

Online Publication Date: 23 March 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The magneto-optical properties of a highly stable ionic magnetic fluid sample containing CdFe2O4 nanoparticles were investigated using static magnetic birefringence, zero-field optical transmissivity, and transmission electron microscopy. From our measurements we found that the transmittivity and the birefringence of the CdFe2O4-based sample is several times greater than a typical magnetic fluid sample (γ-Fe2O3 based), giving this magnetic material great potential for magneto-optics applications. We also found that the birefringence can be increased by several orders of magnitude, allowing full manipulation of the observed negative differential transmitted optical intensity feature. © 2004 American Institute of Physics.
Show PACS
78.20.Ls Magneto-optical effects
75.50.Mm Magnetic liquids
75.50.Tt Fine-particle systems; nanocrystalline materials
75.50.Gg Ferrimagnetics

Large positive magnetoresistance in nonstoichiometric NiMnSb thin films on silicon

W. R. Branford, S. K. Clowes, M. H. Syed, Y. V. Bugoslavsky, S. Gardelis, J. Androulakis, J. Giapintzakis, C. E. A. Grigorescu, A. V. Berenov, S. B. Roy, and L. F. Cohen

Appl. Phys. Lett. 84, 2358 (2004); http://dx.doi.org/10.1063/1.1691172 (3 pages) | Cited 12 times

Online Publication Date: 23 March 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report a systematic study of the transport properties of pulsed-laser-deposited NiMnSb films on silicon as a function of film thickness. A low-temperature upturn is observed in the resistivity for film thicknesses of 130 nm and below. The resistivity minimum corresponds to the maximum in the positive magnetoresistance for all samples. As the film thickness decreases, the magnitude of both the resistivity upturn and the magnetoresistance increase. There is no feature associated with the upturn in the low-field Hall resistivity, which becomes systematically more electron dominated as the film thickness decreases and the temperature increases. This has implications for the use of NiMnSb as a spin injector for spintronic applications. The positive magnetoresistance of the 5 nm sample is greater than 100% at 200 K in 8 T. Further enhancement of the magnetoresistance occurs for field parallel, rather than perpendicular, to the film surface. The magnetoresistance behavior is compared to various model systems, including the band-gap tuning found in the silver chalcogenides, disorder-induced weak localization, and the emerging class of “bad metal” ferromagnets. © 2004 American Institute of Physics.
Show PACS
75.50.Cc Other ferromagnetic metals and alloys
73.61.At Metal and metallic alloys
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
75.47.Np Metals and alloys
71.20.Be Transition metals and alloys
72.15.Gd Galvanomagnetic and other magnetotransport effects

Magnetic domain structure of a La0.7Sr0.3MnO3 (001) surface observed by a spin-polarized scanning electron microscope

M. Konoto, T. Kohashi, K. Koike, T. Arima, Y. Kaneko, Y. Tomioka, and Y. Tokura

Appl. Phys. Lett. 84, 2361 (2004); http://dx.doi.org/10.1063/1.1690463 (3 pages) | Cited 14 times

Online Publication Date: 23 March 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The magnetization vector distribution at a cleaved surface of La0.7Sr0.3MnO3 (001) crystal has been quantitatively analyzed by using a newly developed low-temperature spin-polarized scanning electron microscope. The magnetic structure essentially consists of two kinds of domains, where magnetizations are parallel or antiparallel to the [110] direction with no surface-normal component. The rhombus-shaped domains range from a few to several tens of micrometers across. The domain structure can be considered to be made by laying down the magnetization from the out-of-surface-plane easy axis to the surface plane to reduce the magnetostatic energy without forming closure domains. © 2004 American Institute of Physics.
Show PACS
75.60.Ch Domain walls and domain structure
75.25.-j Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source x-ray scattering, etc.)
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)
68.35.B- Structure of clean surfaces (and surface reconstruction)

Magnetic anisotropy and structure of epitaxial permalloy films sputter-deposited on Nb(110)

R. Loloee, S. Urazhdin, W. P. Pratt, H. Geng, and M. A. Crimp

Appl. Phys. Lett. 84, 2364 (2004); http://dx.doi.org/10.1063/1.1691176 (3 pages) | Cited 4 times

Online Publication Date: 23 March 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Epitaxial Permalloy™ (Py) thin films sputter-deposited onto epitaxial Nb with and without a Cu buffer layer have been investigated. Transmission electron microscopy was used to characterize the morphology of the Nb/Py/Cu and Nb/Cu/Py multilayers. Rotational magnetization measurements indicated significant differences in the magnetic anisotropy of the films. A phenomenological model taking into account uniaxial anisotropy agree well with the data, and provides a simple method for determinating the anisotropy strength. The correlations between the crystal structures and the magnetic properties are discussed. © 2004 American Institute of Physics.
Show PACS
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
75.50.Bb Fe and its alloys
75.30.Gw Magnetic anisotropy
68.55.-a Thin film structure and morphology
68.37.Lp Transmission electron microscopy (TEM)

Structural, magnetic, and transport properties of thin films of the Heusler alloy Co2MnSi

L. J. Singh, Z. H. Barber, Y. Miyoshi, Y. Bugoslavsky, W. R. Branford, and L. F. Cohen

Appl. Phys. Lett. 84, 2367 (2004); http://dx.doi.org/10.1063/1.1690868 (3 pages) | Cited 33 times

Online Publication Date: 23 March 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Thin films of Co2MnSi have been grown on a-plane sapphire substrates from three elemental targets by dc magnetron cosputtering. These films are single phase, have a strong (110) texture, and a saturation magnetization of 4.95μB/formula unit at 10 K. Films grown at the highest substrate temperature of 715 K showed the lowest resistivity (47 μΩ cm at 4.2 K) and the lowest coercivity (18 Oe). The spin polarization of the transport current was found to be of the order of 54% as determined by point contact Andreev reflection spectroscopy. A decrease in saturation magnetization with a decrease in film thickness and different transport behavior in thinner films indicate graded disorder in these films grown on nonlattice matched substrates. © 2004 American Institute of Physics.
Show PACS
81.15.Cd Deposition by sputtering
72.15.Gd Galvanomagnetic and other magnetotransport effects
75.47.Np Metals and alloys
75.50.Cc Other ferromagnetic metals and alloys
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
68.55.-a Thin film structure and morphology
75.70.Ak Magnetic properties of monolayers and thin films

Control of resistance of a magnetoresistive manganite by spin injection

T. Ono, A. Kogusu, S. Morimoto, S. Nasu, A. Masuno, T. Terashima, and M. Takano

Appl. Phys. Lett. 84, 2370 (2004); http://dx.doi.org/10.1063/1.1690877 (3 pages) | Cited 6 times

Online Publication Date: 23 March 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report a spin-injection effect found for a manganite using a specially fabricated sample. A wire of La0.7Sr0.3MnO3 was patterned by means of focused ion beam etching, and the center was subsequently lightly irradiated with Ga+ ions. The ferromagnetic Curie temperature was reduced locally by the irradiation from TC to TC′, and thus a sequential ferromagnetic/paramagnetic/ferromagnetic structure was realized along the wire between TC and TC′. The injection of spin-polarized current from the ferromagnetic manganite into the paramagnetic part rendered the latter ferromagnetic and more conductive. This can be explained by assuming the suppression of spin fluctuation in the paramagnet by the spins injected. © 2004 American Institute of Physics.
Show PACS
75.50.Dd Nonmetallic ferromagnetic materials
75.20.Ck Nonmetals
72.20.My Galvanomagnetic and other magnetotransport effects
75.47.Gk Colossal magnetoresistance
75.47.Lx Magnetic oxides
75.30.Ds Spin waves
75.40.Gb Dynamic properties (dynamic susceptibility, spin waves, spin diffusion, dynamic scaling, etc.)
61.80.Jh Ion radiation effects
81.65.Cf Surface cleaning, etching, patterning
85.75.-d Magnetoelectronics; spintronics: devices exploiting spin polarized transport or integrated magnetic fields
72.25.Hg Electrical injection of spin polarized carriers

Electromagnetic radiation produced by avalanches in the magnetization reversal of Mn12-acetate

J. Tejada, E. M. Chudnovsky, J. M. Hernandez, and R. Amigó

Appl. Phys. Lett. 84, 2373 (2004); http://dx.doi.org/10.1063/1.1691501 (3 pages) | Cited 25 times

Online Publication Date: 23 March 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Electromagnetic radiation produced by avalanches in the magnetization reversal of Mn12-acetate has been measured. Short bursts of radiation have been detected, with intensity significantly exceeding the intensity of the blackbody radiation from the sample. A model based upon superradiance from inversely populated spin levels has been suggested. © 2004 American Institute of Physics.
Show PACS
75.60.Jk Magnetization reversal mechanisms
78.45.+h Stimulated emission
75.50.Xx Molecular magnets

Ferromagnetism and magnetoresistance of Co–ZnO inhomogeneous magnetic semiconductors

Shi-shen Yan, C. Ren, X. Wang, Y. Xin, Z. X. Zhou, L. M. Mei, M. J. Ren, Y. X. Chen, Y. H. Liu, and H. Garmestani

Appl. Phys. Lett. 84, 2376 (2004); http://dx.doi.org/10.1063/1.1690881 (3 pages) | Cited 44 times

Online Publication Date: 23 March 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Co–ZnO inhomogeneous magnetic semiconductor thin films were synthesized on the subnanometer scale by sputtering. Room temperature ferromagnetism with high magnetization was found. Large negative magnetoresistance of 11% was found at room temperature, and its value increased with a decrease in temperature up to 36% at 4.8 K. The mechanism for large negative magnetoresistance is discussed. © 2004 American Institute of Physics.
Show PACS
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
75.47.Pq Other materials
72.20.My Galvanomagnetic and other magnetotransport effects
75.50.Pp Magnetic semiconductors
75.50.Dd Nonmetallic ferromagnetic materials
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close