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

3 Feb 2003

Volume 82, Issue 5, pp. 665-834

Issue Cover Spotlight Figure

Appl. Phys. Lett. 82, 775 (2003); http://dx.doi.org/10.1063/1.1541091 (3 pages)

Sebastiaan van Dijken, Xin Jiang, and Stuart S. P. Parkin
Enlarge Image | Read More
Page 2 of 3 Pages Previous Page Next Page | Jump to Page
back to top
RSS Feeds

Reversible barrier height changes in hydrogen-sensitive Pd/GaN and Pt/GaN diodes

Jihyun Kim, F. Ren, B. P. Gila, C. R. Abernathy, and S. J. Pearton

Appl. Phys. Lett. 82, 739 (2003); http://dx.doi.org/10.1063/1.1541944 (3 pages) | Cited 33 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The forward current of Pd/GaN and Pt/GaN Schottky diodes is found to increase significantly upon introduction of H2 into a N2 ambient. Analysis of the current–voltage characteristics as a function of temperature showed that the current increase is due to a decrease in effective barrier height through a decrease in metal work function upon absorption of hydrogen. The introduction of 10% H2 into a N2 ambient was found to lower the effective barrier height of Pd on GaN by 50 ∼ 70 meV over the temperature range of 298 to ∼ 423 K and of Pt on GaN by 30 ∼ 60 meV over the range of 443 to ∼ 473 K. The magnitude of the changes increased with temperature due to the effective cracking of the H2. The changes in barrier height were completely reversible upon restoration of N2 ambient. © 2003 American Institute of Physics.
Show PACS
85.30.Hi Surface barrier, boundary, and point contact devices
85.30.Kk Junction diodes
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing
85.30.De Semiconductor-device characterization, design, and modeling
73.30.+y Surface double layers, Schottky barriers, and work functions
82.80.-d Chemical analysis and related physical methods of analysis
68.43.Mn Adsorption kinetics

Growth and structural analysis of metalorganic chemical vapor deposited (11math0) MgxZn1−xO (0<x<0.33) films on (01math2) R-plane Al2O3 substrates

S. Muthukumar, J. Zhong, Y. Chen, Y. Lu, and T. Siegrist

Appl. Phys. Lett. 82, 742 (2003); http://dx.doi.org/10.1063/1.1541950 (3 pages) | Cited 32 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
MgxZn1−xO (0<x<0.33) thin films were grown on R-plane (01math2) sapphire substrate by metalorganic chemical vapor deposition. It was found that a thin ZnO buffer layer with a minimum thickness of ∼50 Å is needed to achieve wurtzite-type MgxZn1−xO films on R-plane sapphire. The x-ray Δω(11math0) rocking curve and Δ2θ(11math0) full width at half maximum for Mg0.18Zn0.82O film were measured to be 0.275° and 0.18°, respectively, indicating strong mosaicity and strain in the films. In-plane reflections show the lower lattice mismatch along the c axis of the MgxZn1−xO films on R-plane sapphire. Optical transmission spectra indicate the good quality of the films. © 2003 American Institute of Physics.
Show PACS
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
68.55.-a Thin film structure and morphology
78.66.Hf II-VI semiconductors
78.40.Fy Semiconductors

Modeling of transport in polycrystalline organic semiconductor films

S. Verlaak, V. Arkhipov, and P. Heremans

Appl. Phys. Lett. 82, 745 (2003); http://dx.doi.org/10.1063/1.1541112 (3 pages) | Cited 68 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We propose a grain-boundary barrier model with an energy distribution of interfacial traps to describe charge transport in polycrystalline organic thin films. The model is applied to the interpretation of charge transport in unintentionally doped pentacene films. It gives an acceptable explanation for the concomitant increase in threshold voltage and mobility, and allows an understanding of the difference between the dopant-concentration and gate-voltage dependences of the mobility. © 2003 American Institute of Physics.
Show PACS
73.61.Ph Polymers; organic compounds
61.72.Mm Grain and twin boundaries
73.50.Dn Low-field transport and mobility; piezoresistance
68.55.-a Thin film structure and morphology
71.20.Rv Polymers and organic compounds

Separation of hot-electron and self-heating effects in two-dimensional AlGaN/GaN-based conducting channels

S. A. Vitusevich, S. V. Danylyuk, N. Klein, M. V. Petrychuk, A. Yu. Avksentyev, V. N. Sokolov, V. A. Kochelap, A. E. Belyaev, V. Tilak, J. Smart, A. Vertiatchikh, and L. F. Eastman

Appl. Phys. Lett. 82, 748 (2003); http://dx.doi.org/10.1063/1.1542928 (3 pages) | Cited 22 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We address experimental and theoretical study of a two-dimensional electron gas transport at low and moderate electric fields. The devices under study are group-III nitride-based (AlGaN/GaN) gateless heterostructures grown on sapphire. The transmission line model patterns of different channel lengths, L, and of the same channel width are used. A strong dependence of the device I–V characteristics on the channel length has been found. We have developed a simple theoretical model to adequately describe the observed peculiarities in the I–V characteristics measured in steady-state and pulsed (10−6 s) regimes. The effect of the Joule heating of a heterostructure is clearly distinguished. The thermal impedance and the channel temperature rise caused by the Joule self-heating have been extracted for the devices of different L at different values of dissipated power. The current reduction due to both self-heating and hot-electron effects is determined quantitatively as a function of the electric field. © 2003 American Institute of Physics.
Show PACS
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
73.50.Fq High-field and nonlinear effects

Simulated carrier transport in smectic mesophase and its comparison with experimental result

A. Ohno and J. Hanna

Appl. Phys. Lett. 82, 751 (2003); http://dx.doi.org/10.1063/1.1536730 (3 pages) | Cited 21 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have investigated charge carrier transport in the smectic mesophases of a liquid crystal, i.e., a 2-phenylnaphthalene derivative, by computational Monte Carlo simulation and time-of-flight experiments. The unique carrier transport properties characterized by field-independent high mobility over 10−3 cm2/V s observed is well explained by a two-dimensional hopping model with a Gaussian distribution of density of states. The deviation of Gaussian distribution, small σ, is determined to be 60 meV in the smectic B phase. This model is proven to be valid by demonstrating a predicted Poole–Frenkel-type behavior at the high electric-field region. © 2003 American Institute of Physics.
Show PACS
72.20.Ht High-field and nonlinear effects
72.20.Ee Mobility edges; hopping transport
72.80.Le Polymers; organic compounds (including organic semiconductors)
72.20.Dp General theory, scattering mechanisms

Effective mass in remotely doped Ge quantum wells

Benjamin Rößner, Giovanni Isella, and Hans von Känel

Appl. Phys. Lett. 82, 754 (2003); http://dx.doi.org/10.1063/1.1541101 (3 pages) | Cited 11 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the dependence of the effective masses on hole density in remotely doped strained Ge layers on relaxed Si0.3Ge0.7 buffers with sheet densities from 2.9×1011 cm−2 to 1.9×1012 cm−2. The masses have been determined using temperature dependent Shubnikov–de Haas oscillations. No noticeable dependence of the mass on the magnetic field has been found. The extrapolated Γ point effective mass has been found to be 0.080 times the free electron mass. From the measured data the variation of the mass with kinetic energy and the shape of the topmost heavy hole subband have been calculated. The results are in good agreement with theoretical predictions. © 2003 American Institute of Physics.
Show PACS
73.21.Fg Quantum wells
73.63.Hs Quantum wells
71.18.+y Fermi surface: calculations and measurements; effective mass, g factor
72.20.My Galvanomagnetic and other magnetotransport effects

Space-charge region-dominated steady-state photoconductance in low-lifetime Si wafers

M. Bail, M. Schulz, and R. Brendel

Appl. Phys. Lett. 82, 757 (2003); http://dx.doi.org/10.1063/1.1541115 (3 pages) | Cited 36 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We investigate the steady-state photoconductance of an oxidized low-lifetime monocrystalline Si wafer with an inversion layer at its surfaces. Photogenerated electrons and holes reduce the band bending and decrease the width of the carrier depleted space-charge region. Mobile charge carriers are stored on both sides of the space-charge region and dominate the photoconductivity at a low illumination intensity. This charge storage effect disappears under accumulation. We present an analytic model for the experimental observations. It is necessary to account for the charge storage effect when deducing low (<10 μs) minority carrier lifetimes on surface-inverted solar Si wafers from one-sun steady-state photoconductance measurements. © 2003 American Institute of Physics.
Show PACS
84.60.Jt Photoelectric conversion
72.40.+w Photoconduction and photovoltaic effects
72.20.Ht High-field and nonlinear effects
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
back to top
RSS Feeds

Magnetoelastic and thermoelastic shape memory effect in a Co–Ni single crystal

W. M. Zhou, Y. Liu, B. H. Jiang, X. Qi, and Y. N. Liu

Appl. Phys. Lett. 82, 760 (2003); http://dx.doi.org/10.1063/1.1539907 (3 pages) | Cited 10 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This letter reports on a study of the magnetomechanical and thermomechanical behavior of a Co–32Ni single crystal. When magnetized along the [001]fcc direction at room temperature in austenite coexited with martensitic state, field-induced strains as high as 4.2% were measured at a field of 12 kOe. The magnetic field-induced strains were recovered during demagnetization, exhibiting a magnetic hysteresis of 5–6 kOe. No field-induced strain was detected if a magnetic field was loaded along another direction. When deformed in compression along the [001]fcc direction at room temperature to a prestrain of 5.4%, about 1.5% strain was recovered during subsequent heating, yielding a recovery rate of 27.8%. For specimens deformed in other crystal directions, no obvious recoverable strain was measured. These experimental phenomena are discussed and interpreted in terms of reversible motions of Shockley partial dislocations. © 2003 American Institute of Physics.
Show PACS
75.80.+q Magnetomechanical effects, magnetostriction
75.50.Cc Other ferromagnetic metals and alloys
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
61.72.Hh Indirect evidence of dislocations and other defects (resistivity, slip, creep, strains, internal friction, EPR, NMR, etc.)
62.20.F- Deformation and plasticity
81.40.Lm Deformation, plasticity, and creep
81.40.Gh Other heat and thermomechanical treatments
61.72.Lk Linear defects: dislocations, disclinations
66.30.Lw Diffusion of other defects

Blocking phenomena in granular magnetic alloys through magnetization, Hall effect, and magnetoresistance experiments

J. C. Denardin, A. B. Pakhomov, A. L. Brandl, L. M. Socolovsky, M. Knobel, and X. X. Zhang

Appl. Phys. Lett. 82, 763 (2003); http://dx.doi.org/10.1063/1.1542678 (3 pages) | Cited 10 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Magnetization and magnetotransport were measured in CoxAg1−x granular composites as a function of temperature and applied magnetic field. A transition from blocked to superparamagnetic behavior with increasing temperatures can be observed in magnetization, giant magnetoresistance and the extraordinary Hall effect measurements. However, the blocking temperature determined from magnetotransport measurements is systematically lower than the one estimated from magnetic measurements. This is due to the selective magnetic scattering, which is enhanced for smaller particles, while the magnetization probes the whole particle size distribution. © 2003 American Institute of Physics.
Show PACS
75.50.Tt Fine-particle systems; nanocrystalline materials
75.47.De Giant magnetoresistance
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
81.05.Rm Porous materials; granular materials
72.15.Gd Galvanomagnetic and other magnetotransport effects

Electronic and magnetic properties of MnN versus MnAs

A. Janotti, Su-Huai Wei, and Laurent Bellaiche

Appl. Phys. Lett. 82, 766 (2003); http://dx.doi.org/10.1063/1.1542672 (3 pages) | Cited 28 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Electronic and magnetic properties of MnN and MnAs compounds in the hypothetical cubic zinc-blende phase are studied using first-principles band structure method. We show that the high electronegativity and small atomic size of N compared to As lead to interesting consequences: MnN has a low-spin antiferromagnetic ground state, whereas MnAs has a high-spin hole mediated ferromagnetic (FM) ground state. Because the Mn d bands are higher in energy than the N p band, Mn is not efficient to generate free holes in the nitrides. Therefore, previous prediction that undoped Ga1−xMnxN diluted alloy can result in room-temperature FM semiconductor should be reexamined. © 2003 American Institute of Physics.
Show PACS
71.20.Nr Semiconductor compounds
75.40.Mg Numerical simulation studies
75.50.Ee Antiferromagnetics
75.50.Dd Nonmetallic ferromagnetic materials
75.10.Lp Band and itinerant models
75.50.Pp Magnetic semiconductors

Junction parameter control of Bi2Sr2CaCu2O8+δ stacked junctions by annealing

K. Inomata, T. Kawae, K. Nakajima, S.-J. Kim, and T. Yamashita

Appl. Phys. Lett. 82, 769 (2003); http://dx.doi.org/10.1063/1.1542679 (3 pages) | Cited 13 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The control of the critical current density (Jc) and the junction resistance (RN) along the c axis of intrinsic Josephson junctions (IJJs) on a high-Tc superconductor is very important for applying the IJJs to electronic devices. For controlling these junction parameters, we have clarified the relationship of Jc, RN, and the carrier density in Bi2Sr2CaCu2O8+δ (Bi-2212) whiskers by changing the carrier density with an annealing process. As a result, the Jc decreased, and the RN increased systematically when the carrier density decreased. The values of Jc and RN could be controlled by a change in the carrier density. © 2003 American Institute of Physics.
Show PACS
74.72.-h Cuprate superconductors
74.50.+r Tunneling phenomena; Josephson effects
74.25.Sv Critical currents
74.25.F- Transport properties
81.40.Gh Other heat and thermomechanical treatments
81.40.Rs Electrical and magnetic properties related to treatment conditions

Ca-doping-induced enhancement of the critical currents of coated conductors grown by ion-beam-assisted deposition

A. Weber, G. Hammerl, A. Schmehl, C. W. Schneider, J. Mannhart, B. Schey, M. Kuhn, R. Nies, B. Utz, and H.-W. Neumueller

Appl. Phys. Lett. 82, 772 (2003); http://dx.doi.org/10.1063/1.1543640 (3 pages) | Cited 10 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
One of the most promising technologies for the fabrication of high-Tc cables is the ion-beam-assisted deposition (IBAD) technique. The performance of the superconductors fabricated by IBAD, and the fabrication costs, are to a great extent determined by the critical current densities of the superconductors’ grain boundaries. Since, in bicrystalline samples, overdoping has been found to improve the transport properties of grain boundaries in high-Tc superconductors, we have explored whether overdoping also enhances the critical currents of IBAD samples. The measurements show that, depending on the critical current density of the superconducting film, Jc (77 K) is increased by factors up to 2.2, also in applied magnetic fields of several tesla. © 2003 American Institute of Physics.
Show PACS
74.25.Sv Critical currents
74.78.-w Superconducting films and low-dimensional structures
74.72.-h Cuprate superconductors
81.15.Jj Ion and electron beam-assisted deposition; ion plating
84.71.Mn Superconducting wires, fibers, and tapes

Comparison of magnetocurrent and transfer ratio in magnetic tunnel transistors with spin-valve bases containing Cu and Au spacer layers

Sebastiaan van Dijken, Xin Jiang, and Stuart S. P. Parkin

Appl. Phys. Lett. 82, 775 (2003); http://dx.doi.org/10.1063/1.1541091 (3 pages) | Cited 20 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The magnetocurrent of magnetic tunnel transistors with spin-valve base structures is found to be nearly insensitive to whether the spacer layer material in the spin valve is Cu or Au. By contrast, the in-plane magnetoresistance of the same spin valves differs by almost a factor of two. Furthermore, the transfer ratio of the transistor structure is an order of magnitude lower for Au compared to Cu spacer layers. We attribute these different behaviors to the significant role of spin-dependent interface scattering for electrons near the Fermi energy but to much weaker such scattering for hot electrons in the energy range considered ( ∼ 1–2 eV). © 2003 American Institute of Physics.
Show PACS
85.75.Dd Magnetic memory using magnetic tunnel junctions
75.47.De Giant magnetoresistance
72.25.Mk Spin transport through interfaces
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)

Flux pinning enhancement in ferromagnetic and superconducting thin-film multilayers

D. B. Jan, J. Y. Coulter, M. E. Hawley, L. N. Bulaevskii, M. P. Maley, Q. X. Jia, B. B. Maranville, F. Hellman, and X. Q. Pan

Appl. Phys. Lett. 82, 778 (2003); http://dx.doi.org/10.1063/1.1542674 (3 pages) | Cited 31 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Flux pinning in high-temperature superconductors such as YBa2Cu3O7−x (YBCO) in the past has been accomplished by pinning the vortex cores. We demonstrate magnetic-domain-induced flux pinning of the magnetic flux of vortices in a ferromagnet-superconductor bilayer consisting of CoPt grown on YBCO, where the ferromagnet has uniaxial perpendicular magnetic anisotropy and a random domain structure. We observe an improvement of the critical current due to magnetic pinning at temperatures close to the transition temperature. © 2003 American Institute of Physics.
Show PACS
74.25.Uv Vortex phases (includes vortex lattices, vortex liquids, and vortex glasses)
74.78.-w Superconducting films and low-dimensional structures
74.72.-h Cuprate superconductors
75.50.Cc Other ferromagnetic metals and alloys
75.70.Ak Magnetic properties of monolayers and thin films
75.30.Gw Magnetic anisotropy
75.70.Kw Domain structure (including magnetic bubbles and vortices)
74.25.Sv Critical currents
74.40.-n Fluctuation phenomena
back to top
RSS Feeds

Leakage currents in high-permittivity thin films

Herbert Schroeder, Sam Schmitz, and Paul Meuffels

Appl. Phys. Lett. 82, 781 (2003); http://dx.doi.org/10.1063/1.1541096 (3 pages) | Cited 21 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Quite often leakage current data through high-permittivity thin films exhibit straight lines in the “Schottky” plot, i.e., log (current density j) versus sqrt (mean applied field), which suggests an electrode-limited current by field-enhanced thermionic emission. Unfortunately, the extracted permittivity at optical frequencies seldom is in agreement with experimental values and often is unacceptably small, i.e., <1. We suggest a model demonstrating that the leakage current in high-permittivity thin films is bulk-limited, but still is showing the characteristic dependence of thermionic emission. This is due to a combination of boundary conditions of the model, low-permittivity thin layers (“dead layer”) at the electrodes and current injection/recombination terms at the injecting/collecting electrodes, respectively. © 2003 American Institute of Physics.
Show PACS
77.55.-g Dielectric thin films
77.22.Ch Permittivity (dielectric function)
79.40.+z Thermionic emission
79.70.+q Field emission, ionization, evaporation, and desorption
73.61.Ng Insulators

Natural-superlattice-structured Bi4Ti3O12–SrBi4Ti4O15 ferroelectric thin films

Akira Shibuya, Minoru Noda, Masanori Okuyama, Hironori Fujisawa, and Masaru Shimizu

Appl. Phys. Lett. 82, 784 (2003); http://dx.doi.org/10.1063/1.1543248 (3 pages) | Cited 14 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Natural superlattice structures of c-axis-oriented Bi4Ti3O12–SrBi4Ti4O15 epitaxial ferroelectric thin films have been grown by pulsed laser deposition on both MgO (001) and SrTiO3 (001) substrates. The epitaxial growth of natural-superlattice-structured Bi4Ti3O12–SrBi4Ti4O15 thin film was confirmed by x-ray diffraction (XRD) θ–2θ scan, pole figure plots, and reciprocal space mappings. The c-axis lattice parameter of the Bi4Ti3O12–SrBi4Ti4O15 thin film became the average of those for Bi4Ti3O12 and SrBi4Ti4O15. The Bi4Ti3O12–SrBi4Ti4O15 thin film on Pt substrate shows that twice remanent polarization (2Pr) and coercive field (2Ec) are 32 μC/cm2 and 190 kV/cm, respectively. © 2003 American Institute of Physics.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.55.-g Dielectric thin films
77.80.Dj Domain structure; hysteresis
68.55.-a Thin film structure and morphology
77.22.Ej Polarization and depolarization
81.15.Fg Pulsed laser ablation deposition

Single-domain properties of 0.67Pb(Mg1/3Nb2/3)O3–0.33PbTiO3 single crystals under electric field bias

Rui Zhang, Bei Jiang, and Wenwu Cao

Appl. Phys. Lett. 82, 787 (2003); http://dx.doi.org/10.1063/1.1541937 (3 pages) | Cited 57 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report a complete set of material properties of single-domain, relaxor-based 0.67Pb(Mg1/3Nb2/3)O3–0.33PbTiO3 [PMN–33%PT] single crystals. Because the single-domain state is unstable in natural conditions, a bias electric field of 0.2 MV/m was applied along the dipole direction of the rhombohedral phase during the measurements. It was found that the electromechanical coupling coefficient k33 and the piezoelectric constant d33 for single-domain PMN–33%PT are 69% and 190 pC/N, respectively. Both of them are much smaller than those of multidomain PMN–33%PT poled along [001] direction. However, the shear piezoelectric constant d15 of single-domain PMN–33%PT reaches 4100 pC/N, which is much higher than that of multidomain PMN–33%PT. © 2003 American Institute of Physics.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.80.Dj Domain structure; hysteresis
77.65.Bn Piezoelectric and electrostrictive constants

Dielectric relaxation and strain behavior of 95.5% Pb(Zn1/3Nb2/3)O3–4.5% PbTiO3 single crystals at cryogenic temperatures

Zhi Yu, Chen Ang, E. Furman, and L. E. Cross

Appl. Phys. Lett. 82, 790 (2003); http://dx.doi.org/10.1063/1.1541936 (3 pages) | Cited 11 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The dielectric behavior of 95.5% Pb(Zn1/3Nb2/3)O3–4.5% PbTiO3 single crystals oriented along 〈001〉 direction with and without dc electric field has been studied at cryogenic temperatures. A pronounced low-temperature dielectric relaxation process was observed below 200 K; the relaxation rate follows the Arrhenius law (τ0 = ∼ 1.0×10−15 s and U = 0.24 eV). An additional dielectric anomaly showed up around 250 K at 10 kHz under a dc electric field. These results indicate rather complicated polarization mechanisms at cryogenic temperatures which clearly need more detailed study. The strain levels at cryogenic temperatures suggest that this material is very promising for space applications, in which the performance at cryogenic temperatures is critical. © 2003 American Institute of Physics.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.80.-e Ferroelectricity and antiferroelectricity
77.65.Ly Strain-induced piezoelectric fields
77.22.Gm Dielectric loss and relaxation
77.22.Ch Permittivity (dielectric function)
77.22.Ej Polarization and depolarization
back to top
RSS Feeds

Nanoscale organic transistors that use source/drain electrodes supported by high resolution rubber stamps

Jana Zaumseil, Takao Someya, Zhenan Bao, Yueh-Lin Loo, Raymond Cirelli, and John A. Rogers

Appl. Phys. Lett. 82, 793 (2003); http://dx.doi.org/10.1063/1.1541941 (3 pages) | Cited 37 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Soft contact lamination and metal-coated elastomeric stamps provide the basis for a convenient and noninvasive approach to establishing high resolution electrical contacts to electroactive organic materials. The features of relief on the stamps define, with nanometer resolution, the geometry and separation of electrically independent electrodes that are formed by uniform, blanket evaporation of a thin metal film onto the stamp. Placing this coated stamp on a flat substrate leads to “wetting” and atomic scale contact that establishes efficient electrical connections. When the substrate supports an organic semiconductor, a gate dielectric and a gate, this soft lamination process yields high performance top contact transistors with source/drain electrodes on the stamp. We use this approach to investigate charge transport through pentacene in transistor structures with channel lengths that span more than three decades: from 250 μm to ∼150 nm. We also report some preliminary measurements on charge transport through organic monolayers using the same laminated transistor structures. © 2003 American Institute of Physics.
Show PACS
85.35.-p Nanoelectronic devices
73.63.Rt Nanoscale contacts
81.07.Lk Nanocontacts
85.30.Pq Bipolar transistors

Aligned carbon nanotubes patterned photolithographically by silver

Shaoming Huang and Albert H. W. Mau

Appl. Phys. Lett. 82, 796 (2003); http://dx.doi.org/10.1063/1.1541939 (3 pages) | Cited 12 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Selective growth of aligned carbon nanotubes (CNTs) by pyrolysis of iron (II) phthalocyanine (FePc) on quartz substrate patterned photolithographically by metallic silver has been demonstrated. Micro/nanopattern of aligned CNTs can be achieved by using a photomask with features on a microscale. With convenient use of simple high-contract black and white films as a photomask, aligned nanotubes patterned with 20 μm resolution in large scale can be fabricated. This practical fabrication of aligned CNTs on patterned conducting substrate could be applied to various device applications of CNTs. © 2003 American Institute of Physics.
Show PACS
81.16.Nd Micro- and nanolithography
85.40.Hp Lithography, masks and pattern transfer
81.16.Rf Micro- and nanoscale pattern formation
81.07.De Nanotubes
61.46.-w Structure of nanoscale materials
81.05.U- Carbon/carbon-based materials
82.30.Lp Decomposition reactions (pyrolysis, dissociation, and fragmentation)

Dot size dependence of vertical and lateral ordering in self-organized PbSe/Pb1−xEuxTe quantum-dot superlattices

G. Springholz, A. Raab, R. T. Lechner, and V. Holy

Appl. Phys. Lett. 82, 799 (2003); http://dx.doi.org/10.1063/1.1539279 (3 pages) | Cited 4 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Self-organized vertical and lateral ordering in PbSe/Pb1−xEuxTe quantum-dot superlattices is investigated as a function of PbSe dot layer thickness. An efficient lateral ordering and face centered cubic-like dot stacking occurs only for PbSe thicknesses between 4–6 monolayers. For smaller thicknesses, no correlations are formed, whereas for larger thicknesses the dots are vertically aligned along the growth direction. These transitions are explained by changes in interlayer dot interactions as a function of the dot size. © 2003 American Institute of Physics.
Show PACS
68.65.Hb Quantum dots (patterned in quantum wells)
68.37.Ps Atomic force microscopy (AFM)

Classical and quantum transport in focused-ion-beam-deposited Pt nanointerconnects

J.-F. Lin, J. P. Bird, L. Rotkina, and P. A. Bennett

Appl. Phys. Lett. 82, 802 (2003); http://dx.doi.org/10.1063/1.1541940 (3 pages) | Cited 45 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We study the electrical properties of Pt nanointerconnects, formed on SiO2 substrates by focused-ion-beam deposition. Studies of their temperature-dependent resistivity reveal a small residual-resistivity ratio, and a Debye temperature that differs significantly from that of pure Pt, indicative of the disordered nature of the nanowires. Their magnetoresistance shows evidence for weak antilocalization at temperatures below 10 K, with a phase-breaking length of ∼100 nm, and a temperature dependence suggestive of quasi-one-dimensional interference. © 2003 American Institute of Physics.
Show PACS
73.63.Rt Nanoscale contacts
73.40.Ns Metal-nonmetal contacts
81.07.Lk Nanocontacts
72.15.Gd Galvanomagnetic and other magnetotransport effects
72.15.Rn Localization effects (Anderson or weak localization)
73.20.Fz Weak or Anderson localization

Fabrication of nanometer-scale mechanical devices incorporating individual multiwalled carbon nanotubes as torsional springs

P. A. Williams, S. J. Papadakis, A. M. Patel, M. R. Falvo, S. Washburn, and R. Superfine

Appl. Phys. Lett. 82, 805 (2003); http://dx.doi.org/10.1063/1.1538346 (3 pages) | Cited 20 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the fabrication of nanometer-scale mechanical devices incorporating multiwalled carbon nanotubes (MWNTs) as the torsional spring elements. We have employed electron beam lithography to pattern device elements directly onto individual MWNTs on a silicon dioxide substrate. The structures were suspended by etching the substrate and subsequent critical-point drying of the sample. We also briefly present characterization of the torsional properties of an individual MWNT. The techniques described are applicable to other nanometer-scale rod-like objects. © 2003 American Institute of Physics.
Show PACS
85.35.Kt Nanotube devices
85.85.+j Micro- and nano-electromechanical systems (MEMS/NEMS) and devices
81.16.Nd Micro- and nanolithography

Chemomechanical surface patterning and functionalization of silicon surfaces using an atomic force microscope

Brent A. Wacaser, Michael J. Maughan, Ian A. Mowat, Travis L. Niederhauser, Matthew R. Linford, and Robert C. Davis

Appl. Phys. Lett. 82, 808 (2003); http://dx.doi.org/10.1063/1.1535267 (3 pages) | Cited 23 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Surface modification and patterning at the nanoscale is a frontier in science with significant possible applications in biomedical technology and nanoelectronics. Here we show that an atomic force microscope (AFM) can be employed to simultaneously pattern and functionalize hydrogen-terminated silicon (111) surfaces. The AFM probe was used to break Si–H and Si–Si bonds in the presence of reactive molecules, which covalently bonded to the scribed Si surface. Functionalized patches and patterned lines of molecules were produced. Linewidths down to 30 nm were made by varying the force at the tip. © 2003 American Institute of Physics.
Show PACS
68.37.Ps Atomic force microscopy (AFM)
68.47.Fg Semiconductor surfaces
81.65.Ps Polishing, grinding, surface finishing
87.85.Qr Nanotechnologies-design
87.85.Rs Nanotechnologies-applications
85.35.-p Nanoelectronic devices
61.50.Lt Crystal binding; cohesive energy
87.80.-y Biophysical techniques (research methods)
81.05.Cy Elemental semiconductors

Ink-jet printing of nanoparticle catalyst for site-selective carbon nanotube growth

Hiroki Ago, Kazuhiro Murata, Motoo Yumura, Junko Yotani, and Sashiro Uemura

Appl. Phys. Lett. 82, 811 (2003); http://dx.doi.org/10.1063/1.1540726 (3 pages) | Cited 36 times

Online Publication Date: 28 January 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on site-selective growth of multiwalled carbon nanotubes (MWNTs) from a Co nanoparticle catalyst patterned by an ink-jet printing (IJP) technique. The dispersion of the Co nanoparticles was employed as “catalyst ink” for the IJP, and the catalyst pattern was subjected to chemical vapor deposition of acetylene gas. The patterned array of MWNTs was obtained with a dot size around 5–30 μm and showed field emission of electrons corresponding to the printed pattern. The present method offers a simple and powerful means to pattern carbon nanotubes at desired positions with any patterns. © 2003 American Institute of Physics.
Show PACS
81.16.Hc Catalytic methods
81.16.Nd Micro- and nanolithography
81.07.De Nanotubes
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
61.46.-w Structure of nanoscale materials
81.07.Bc Nanocrystalline materials
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
68.55.A- Nucleation and growth
79.70.+q Field emission, ionization, evaporation, and desorption
61.48.-c Structure of fullerenes and related hollow and planar molecular structures
82.33.Ya Chemistry of MOCVD and other vapor deposition methods
Page 2 of 3 Pages Previous Page Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close