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

14 Sep 2009

Volume 95, Issue 11, Articles (11xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 95, 113101 (2009); http://dx.doi.org/10.1063/1.3197646 (3 pages)

Jesse J. Cole, En-Chiang Lin, Chad R. Barry, and Heiko O. Jacobs
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Formation of creases on the surfaces of elastomers and gels

Wei Hong, Xuanhe Zhao, and Zhigang Suo

Appl. Phys. Lett. 95, 111901 (2009); http://dx.doi.org/10.1063/1.3211917 (3 pages) | Cited 27 times

Online Publication Date: 14 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
When a block of an elastomer is bent, the compressed surface may form a crease. The critical strain for creasing measured experimentally is known to disagree with that predicted by linear perturbation analysis. This paper calculates the critical strain by comparing the elastic energy in a creased body and that in a smooth body. This difference in energy is expressed by a scaling relation. Critical conditions for creasing are determined for elastomers subject to general loads and gels swelling under constraint. The theoretical results are compared with existing experimental observations.
Show PACS
82.70.Gg Gels and sols
62.20.D- Elasticity
81.40.Jj Elasticity and anelasticity, stress-strain relations

Interband transitions of InAsxSb1−x alloy films

T. J. Kim, J. J. Yoon, S. Y. Hwang, D. E. Aspnes, Y. D. Kim, H. J. Kim, Y. C. Chang, and J. D. Song

Appl. Phys. Lett. 95, 111902 (2009); http://dx.doi.org/10.1063/1.3216056 (3 pages) | Cited 6 times

Online Publication Date: 14 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report pseudodielectric-function spectra from 1.5 to 6.0 eV of InAsxSb1−x ternary alloys obtained by spectroscopic ellipsometry. Energies of the E1, E1+Δ1, E0′, E0′+Δ0′, E2, E2+Δ2, E2′, E2′+Δ2, and E1′ critical points (CPs) were obtained from numerically calculated second derivatives, and identifications established by band-structure calculations using the linear augmented Slater-type orbital method. The E2, E2+Δ2, E2′, and E2′+Δ2 CP structures cross with increasing As-composition. Two saddle-point transitions, Δ5cu-Δ5vu and Δ5cl−Δ5vu, are found for InSb.
Show PACS
81.05.Ea III-V semiconductors
78.66.Fd III-V semiconductors
68.55.ag Semiconductors
71.20.Nr Semiconductor compounds
71.15.-m Methods of electronic structure calculations
71.45.Gm Exchange, correlation, dielectric and magnetic response functions, plasmons

Optical and microstructural studies of InGaN/GaN quantum dot ensembles

S. C. Davies, D. J. Mowbray, F. Ranalli, P. J. Parbrook, Q. Wang, T. Wang, B. S. Yea, B. J. Sherliker, M. P. Halsall, R. J. Kashtiban, and U. Bangert

Appl. Phys. Lett. 95, 111903 (2009); http://dx.doi.org/10.1063/1.3226645 (3 pages) | Cited 4 times

Online Publication Date: 14 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An optical and structural study of InGaN/GaN quantum dots (QDs) is reported. With increasing InGaN deposition time, the dominant emission changes from wetting layer (WL) to QDs, and a strong redshift of the emission occurs. Emission from localized WL states is observed, with a density and nature very different to that due to the QDs. Structural measurements reveal a disordered WL, consistent with the form of the WL photoluminescence excitation spectra.
Show PACS
78.67.Hc Quantum dots
81.07.Ta Quantum dots
78.55.Cr III-V semiconductors
81.05.Ea III-V semiconductors
73.21.La Quantum dots

Resonance transmission or absorption in deep gratings explained by magnetic polaritons

L. P. Wang and Z. M. Zhang

Appl. Phys. Lett. 95, 111904 (2009); http://dx.doi.org/10.1063/1.3226661 (3 pages) | Cited 17 times

Online Publication Date: 14 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Resonance transmission or absorption has been observed in metallic deep gratings and previously characterized as coupled surface plasmon polaritons or Fabry–Pérot-like resonances. This letter provides a quantitative explanation of this phenomenon by means of localized magnetic polaritons. Rigorous coupled-wave analysis is used to predict the spectral transmittance and absorptance of subwavelength gratings. The resonance condition is compared with that predicted by the LC circuit model. Some geometric effects that cannot be explained by previous models can be well understood in terms of magnetic polaritons. The insight gained from this study may facilitate future design and applications of subwavelength periodic structures.
Show PACS
71.36.+c Polaritons (including photon-phonon and photon-magnon interactions)
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)

Preferential oxidation of stacking faults in epitaxial off-axis (111) 3C-SiC films

A. Severino, M. Camarda, S. Scalese, P. Fiorenza, S. Di Franco, C. Bongiorno, A. La Magna, and F. La Via

Appl. Phys. Lett. 95, 111905 (2009); http://dx.doi.org/10.1063/1.3227886 (3 pages) | Cited 3 times

Online Publication Date: 14 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The effect of thermal dry oxidation on an off-axis (111) 3C-SiC film have been studied in order to subsequently realize a metal-oxide-semiconductor structure. A morphological characterization of the SiO2 surface, grown at 1200 °C in an O2 flux, pointed out some defect-related effects as a consequence of the preferential oxidation of stacking faults over the (111) 3C-SiC surface. Scanning electron microscopy and atomic force microscopy confirmed such a hypothesis. Stacking faults are seen as promoters of a local polarity inversion in (111) 3C-SiC, from Si- to C-terminated surface, resulting in a higher oxidation rate as compared to defect-free zones.
Show PACS
61.72.Nn Stacking faults and other planar or extended defects
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)
68.37.Ps Atomic force microscopy (AFM)
81.65.Mq Oxidation
68.55.ag Semiconductors

Thermal stability of epitaxial Fe films on GaN(0001)

Cunxu Gao, Oliver Brandt, Hans-Peter Schönherr, Uwe Jahn, Jens Herfort, and Bernd Jenichen

Appl. Phys. Lett. 95, 111906 (2009); http://dx.doi.org/10.1063/1.3230004 (3 pages) | Cited 7 times

Online Publication Date: 14 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Epitaxial Fe films are grown on GaN(0001) by molecular beam epitaxy at 50 °C. Several samples of one Fe/GaN structure are subjected to rapid thermal annealing from 300 to 950 °C. Using a variety of experimental techniques, we examine the impact of this annealing step upon the morphological, structural, and magnetic properties of these samples. The results demonstrate that the material system Fe/GaN is thermally stable up to a temperature of 700 °C.
Show PACS
68.60.Dv Thermal stability; thermal effects
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
75.70.Ak Magnetic properties of monolayers and thin films

Extremely anisotropic, direction-dependent elastic grain interaction: The case of ultrathin films

U. Welzel, A. Kumar, and E. J. Mittemeijer

Appl. Phys. Lett. 95, 111907 (2009); http://dx.doi.org/10.1063/1.3224904 (3 pages) | Cited 8 times

Online Publication Date: 15 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The elastic grain interaction in a 50-nm-thick Pd thin film sputter deposited on a single-crystalline Si substrate has been investigated employing x-ray diffraction residual stress analysis. The occurrence of pronouncedly nonlinear sin2 ψ-plots (i.e., plots of the lattice strain for a particular hkl reflection versus the squared sine of the inclination angle of the diffraction vector with respect to the surface normal ψ) in diffraction stress analysis for the 200 and 222 reflections revealed anisotropic grain interaction of severity not observed before near free surfaces. Application of a direction-dependent elastic grain-interaction model showed that the grain interaction perpendicular to the surface is of Reuss character, whereas the in-plane grain interaction is of Voigt character.
Show PACS
68.60.Bs Mechanical and acoustical properties
68.55.-a Thin film structure and morphology
81.15.Cd Deposition by sputtering
81.40.Jj Elasticity and anelasticity, stress-strain relations
62.20.D- Elasticity

Electron diffractive imaging of nano-objects using a guided method with a dynamic support

Roman Dronyak, Keng S. Liang, Yuri P. Stetsko, Ting-Kuo Lee, Chi-Kai Feng, Jin-Sheng Tsai, and Fu-Rong Chen

Appl. Phys. Lett. 95, 111908 (2009); http://dx.doi.org/10.1063/1.3227837 (3 pages) | Cited 8 times

Online Publication Date: 15 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present a phase recovery technique that utilizes a guiding method with a dynamic support to reconstruct the shape and exit wave of a single MgO nanoparticle in a coherent electron diffraction experiment. The proposed method provides an optimal solution deduced from the electron diffraction pattern alone. The recovered shape has spatial resolution 3.1 nm. The complex exit wave encodes the projected atomic structure of the nanocrystal with resolution about 0.15 nm, and agrees with a multislice simulation. The possibility of imaging nanosized objects at diffraction-limited resolution using a field emission electron microscope is thus demonstrated.
Show PACS
61.46.Df Structure of nanocrystals and nanoparticles ("colloidal" quantum dots but not gate-isolated embedded quantum dots)
68.37.Vj Field emission and field-ion microscopy

Influence of surface morphology on the optical property of vertically aligned ZnO nanorods

Sachindra Nath Das, Jyoti Prakash Kar, Ji-Hyuk Choi, S. Byeon, Y. D. Jho, and Jae-Min Myoung

Appl. Phys. Lett. 95, 111909 (2009); http://dx.doi.org/10.1063/1.3231615 (3 pages) | Cited 5 times

Online Publication Date: 17 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this letter we have studied an influence of surface morphology on the optical property of vertically aligned ZnO nanorods. At low temperature the near band edge excitonic emission shows a strong dependence on surface morphology. A prominent and well resolved near band edge photoluminescence (PL) peak was obtained for nanowires with decreasing diameter and thus assigned due to the contributions to the optical properties of individual nanorods. Depending on surface morphology, the difference in low temperature PL property is attributed to the tailing of the density of states due to the potential fluctuations in randomly distributed intrinsic defects.
Show PACS
78.67.Lt Quantum wires
73.22.Lp Collective excitations
78.68.+m Optical properties of surfaces
73.21.Hb Quantum wires
78.55.Et II-VI semiconductors
71.35.-y Excitons and related phenomena
68.35.bg Semiconductors

Diffusion of hydrogen vacancy in Na3AlH6

Jianchuan Wang, Yong Du, Honghui Xu, Lixian Sun, and Zi-kui Liu

Appl. Phys. Lett. 95, 111910 (2009); http://dx.doi.org/10.1063/1.3225152 (3 pages) | Cited 2 times

Online Publication Date: 17 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We perform first-principles calculations to investigate neutral and charged H vacancies dynamics involving vacancy formation and diffusion in Na3AlH6. We find that the activation barrier for local diffusion (diffusion within AlH5 unit) is smaller than that of nonlocal diffusion (diffusion between AlH6 and AlH5 units) for all types of H vacancies; H diffusion in Na3AlH6 is dominated by mobility of positively charged H vacancies. Furthermore, our results confirm that the observed highly mobile species by anelastic spectroscopy measurements is probably the positively charged H vacancies in the form of local diffusion.
Show PACS
66.30.Lw Diffusion of other defects
84.60.-h Direct energy conversion and storage
61.72.jd Vacancies

Single-shot ultrafast electron diffraction with a laser-accelerated sub-MeV electron pulse

Shigeki Tokita, Shunsuke Inoue, Shinichiro Masuno, Masaki Hashida, and Shuji Sakabe

Appl. Phys. Lett. 95, 111911 (2009); http://dx.doi.org/10.1063/1.3226674 (3 pages) | Cited 4 times

Online Publication Date: 17 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have demonstrated single-shot measurement of electron diffraction patterns for a single-crystal gold foil using 340 keV electron pulses accelerated by intense femtosecond laser pulses with an intensity of 2×1018 W/cm2. The measured electron beam profile is faithfully reproduced by the numerical simulation of the electron trajectory, providing evidence that the electron pulse spontaneously expands in time owing to the velocity spread produced in the acceleration process, but is not distorted in an irreversible nonlinear manner. This study shows that the laser acceleration is promising for the development of pulse compression methods for single-shot femtosecond electron diffraction.
Show PACS
61.05.J- Electron diffraction and scattering
06.60.Jn High-speed techniques (microsecond to femtosecond)

Blister formation in ion-implanted GaAs: Role of diffusivity

R. R. Collino, B. B. Dick, F. Naab, Y. Q. Wang, M. D. Thouless, and R. S. Goldman

Appl. Phys. Lett. 95, 111912 (2009); http://dx.doi.org/10.1063/1.3224199 (3 pages) | Cited 4 times

Online Publication Date: 17 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have investigated the influence of substrate temperature during implantation, Timplant, on blister formation in GaAs:N layers produced by N ion implantation followed by rapid thermal annealing. Similar depths of popped blisters (craters) and damage profiles were observed for both low and high Timplant. This is in contrast to reports of Timplant-dependent blister formation in higher-diffusivity systems such as GaAs:H and Si:H. The apparent Timplant-insensitivity of blister formation in GaAs:N is likely due to the lower diffusivity of N in GaAs in comparison to that of H in GaAs and Si.
Show PACS
81.05.Ea III-V semiconductors
66.30.H- Self-diffusion and ionic conduction in nonmetals
61.72.Cc Kinetics of defect formation and annealing
81.40.Gh Other heat and thermomechanical treatments
61.72.uj III-V and II-VI semiconductors
68.55.ag Semiconductors

Broadband optical amplification in silicate glass ceramics containing Li2ZnSiO4:Cr4+ nanocrystals

Yixi Zhuang, Yu Teng, Jin Luo, Bin Zhu, Yingzhi Chi, E Wu, Heping Zeng, and Jianrong Qiu

Appl. Phys. Lett. 95, 111913 (2009); http://dx.doi.org/10.1063/1.3231439 (3 pages) | Cited 6 times

Online Publication Date: 18 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Transparent glass ceramics containing Li2ZnSiO4:Cr4+ nanocrystals are prepared and their optical properties are investigated. The glass ceramics show intense broadband infrared luminescence and long fluorescence lifetime of about 90 μs. The single-pass optical amplification is demonstrated on a traditional two-wave mixing configuration. The optical gain efficiency is about 1.27 cm−1 when the excitation power is 0.80 W. The optical gain shows the similar wavelength dependence with luminescence properties. The transparent glass ceramics containing Li2ZnSiO4:Cr4+ nanocrystals have potential application as broadband gain media in optical communication system.
Show PACS
81.05.Pj Glass-based composites, vitroceramics
42.65.Jx Beam trapping, self-focusing and defocusing; self-phase modulation
78.47.nj Four-wave mixing spectroscopy
81.07.Bc Nanocrystalline materials
78.67.Bf Nanocrystals, nanoparticles, and nanoclusters
42.79.Sz Optical communication systems, multiplexers, and demultiplexers
42.70.Ce Glasses, quartz
78.55.Hx Other solid inorganic materials

Twin Cu nanowires using energetic beams

Yongfeng Zhang and Hanchen Huang

Appl. Phys. Lett. 95, 111914 (2009); http://dx.doi.org/10.1063/1.3232240 (3 pages) | Cited 3 times

Online Publication Date: 18 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
It is well established that twinning can increase the mechanical strength of metallic (such as Cu) nanowires. This letter proposes a method of introducing twin boundaries into Cu nanowires using energetic beams and demonstrates the feasibility through classical molecular dynamics simulations. The authors show that after electron bombardment twinning occurs in Cu nanowires. The twinning consists of three steps: nucleation of hexagonal-close-packed (HCP) layer, growth of the HCP layer, and interaction of nearby HCP layers. The twinning method reported here offers a mechanism of improving the mechanical strength of metallic nanowires.
Show PACS
81.07.Vb Quantum wires
62.23.Hj Nanowires
61.72.Mm Grain and twin boundaries
61.43.Bn Structural modeling: serial-addition models, computer simulation
61.80.Fe Electron and positron radiation effects

Semiconductor to metal transition characteristics of VO2 thin films grown epitaxially on Si (001)

A. Gupta, R. Aggarwal, P. Gupta, T. Dutta, Roger J. Narayan, and J. Narayan

Appl. Phys. Lett. 95, 111915 (2009); http://dx.doi.org/10.1063/1.3232241 (3 pages) | Cited 16 times

Online Publication Date: 18 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report semiconductor to metal transition (SMT) characteristics of vanadium dioxide (VO2) grown epitaxially on Si (001) at 500 °C. The epitaxial integration with Si (001) was achieved by using epitaxial tetragonal yttria-stabilized zirconia (YSZ) as an intermediate buffer layer, which was grown in situ. From x-ray (θ-2θ and ϕ-scan) and electron diffraction studies, we established that VO2 and YSZ grow in (020) and (001) orientations, respectively, on Si (001) substrate and epitaxial relationship was established to be “VO2[001] or VO2[100]”//YSZ[110]//Si [100] and VO2(010)//YSZ(001)//Si(001). VO2/YSZ/Si(001) heterostructures showed approximately three orders of magnitude reversible change in resistivity and hysteresis of ∼ 6 K upon traversing the transition temperature. A 10 °C increase in the SMT temperature of these VO2 films, compared to the value reported for bulk VO2, has been explained on the basis of uniaxial stress along the c-axis, which can stabilize the covalent monoclinic phase up to higher temperatures. A correlation between in-plane orientations of the film and the transition width has also been suggested, which is consistent with our previously published thermodynamic model.
Show PACS
71.30.+h Metal-insulator transitions and other electronic transitions
72.60.+g Mixed conductivity and conductivity transitions
68.60.Bs Mechanical and acoustical properties
68.55.A- Nucleation and growth
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
73.61.Ng Insulators
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close