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13 Oct 2003

Volume 83, Issue 15, pp. 2991-3216

Issue Cover Spotlight Figure

Appl. Phys. Lett. 83, 3159 (2003); http://dx.doi.org/10.1063/1.1617378 (3 pages)

Zheng Wei Pan, Sheng Dai, David B. Beach, and Douglas H. Lowndes
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Role of boron for defect evolution in hydrogen-implanted silicon

J. K. Lee, T. Höchbauer, R. D. Averitt, and M. Nastasi

Appl. Phys. Lett. 83, 3042 (2003); http://dx.doi.org/10.1063/1.1616979 (3 pages) | Cited 9 times

Online Publication Date: 7 October 2003

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The mechanism underlying the exfoliation phenomenon in B+H coimplanted Si is presented. Compared with only H implantation, H-implanted Si samples that received a B preimplant were observed to have a decrease in implantation-induced lattice damage, in spite of enhanced blistering behavior, which was more pronounced for nonactivated B. Infrared spectroscopy showed that the concentration of Si–H multivacancy defects was also decreased in the B+H coimplanted Si relative to H-only-implanted Si. These decreases in the damage and H-defect density suggest that the lower damage in the B+H coimplanted Si results from a reduction in H-trap density, which in turn enhances H diffusion and the kinetics of blistering. This reduction in lattice damage and H–Si-defect complexes is attributed to the formation of a kinetically active B–Si interstitial complex that is prevalent in nonactivated B-implanted Si. © 2003 American Institute of Physics.
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61.80.Jh Ion radiation effects
61.82.Fk Semiconductors
61.72.J- Point defects and defect clusters
66.30.J- Diffusion of impurities
78.30.Hv Other nonmetallic inorganics
61.72.uf Ge and Si

Enhancement of the recording stability of a photorefractive polymer composite by the introduction of a trapping layer

Won-Sun Kim, Jong-Woo Lee, and Jung-Ki Park

Appl. Phys. Lett. 83, 3045 (2003); http://dx.doi.org/10.1063/1.1606885 (3 pages) | Cited 4 times

Online Publication Date: 7 October 2003

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A photorefractive polymer composite containing a trapping layer which exhibits a significant enhancement in its photorefractivity is reported. The photorefractive polymer composite containing a trapping layer showed a grating life time as high as 600 s, while the grating life time was only 7 s in the photorefractive polymer composite without a trapping layer. The grating growth rate was found to be unaffected by the introduction of a trapping layer. The diffraction efficiency and gain coefficient also increased by the introduction of a trapping layer. The enhancement in the photorefractive properties is due to the increase in the space-charge field developed in the photorefractive polymer composite containing a trapping layer. © 2003 American Institute of Physics.
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42.70.Jk Polymers and organics
42.70.Gi Light-sensitive materials
42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials
42.79.Vb Optical storage systems, optical disks
42.79.Dj Gratings

Effect of intrinsic point defects on copper precipitation in large-diameter Czochralski silicon

Zhenqiang Xi, Deren Yang, Jin Xu, Yujie Ji, Duanlin Que, and H. J. Moeller

Appl. Phys. Lett. 83, 3048 (2003); http://dx.doi.org/10.1063/1.1617377 (3 pages) | Cited 14 times

Online Publication Date: 7 October 2003

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Effect of intrinsic point defects on copper precipitation in large-diameter Czochralski silicon annealed at 1100 °C under air cooling was studied by means of scanning infrared microscopy (SIRM), optical microscopy (OM), and transmission electron microscopy (TEM). The SIRM images showed that, in the A-defect zone of the Cu-contaminated silicon wafers, the copper-precipitate colonies with larger size were observed, while in the D-defect zone almost no copper precipitates could be observed. However, the OM results revealed that the density of etching pits in the D-defect zone was higher than that in the A-defect zone, indicating that the copper precipitates with smaller size and higher density formed in the D-defect zone. The TEM investigation showed that the size of copper precipitate colonies in the A-defect zone was about 300 nm, while that in the D-defect zone was about 50 nm. It is considered that as-grown vacancies in the D-defect zone enhanced the nucleation of copper precipitates but hindered their growth, whereas the role of as-grown interstitial silicon on copper precipitation was inverse. © 2003 American Institute of Physics.
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64.75.-g Phase equilibria
81.10.Dn Growth from solutions
81.10.Fq Growth from melts; zone melting and refining
81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
61.72.J- Point defects and defect clusters
61.72.Cc Kinetics of defect formation and annealing
61.72.Yx Interaction between different crystal defects; gettering effect

Electronic structure of acceptor-donor complexes in silicon

E. Atoro, Y. Ohama, and Y. Hayafuji

Appl. Phys. Lett. 83, 3051 (2003); http://dx.doi.org/10.1063/1.1618378 (3 pages) | Cited 1 time

Online Publication Date: 7 October 2003

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The electronic structure of trimer acceptor-donor complexes in silicon Si clusters is studied using the ab initio discrete variational-Xα molecular-orbital (MO) method. The trimer complexes In2D (D = phosphorus P, arsenic As, antimony Sb, or bismuth Bi) consist of two indium In acceptor elements and a centered donor element D from the group V elements. Calculations are performed under the assumption that the three atoms are arranged in the nearest neighbor substitutional trimer configuration. Results indicate that the trimer complexes act as shallower acceptors having smaller ionization activation energies than In acceptor. The potential of In2D as an acceptor in Si is then discussed and In2D is proposed as a promising acceptor for the formation of channels and source/drains in ultralarge scaled integration. © 2003 American Institute of Physics.
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71.55.Cn Elemental semiconductors
71.15.Ap Basis sets (LCAO, plane-wave, APW, etc.) and related methodology (scattering methods, ASA, linearized methods, etc.)

How to estimate the Green’s function of a heterogeneous medium between two passive sensors? Application to acoustic waves

Arnaud Derode, Eric Larose, Michel Campillo, and Mathias Fink

Appl. Phys. Lett. 83, 3054 (2003); http://dx.doi.org/10.1063/1.1617373 (3 pages) | Cited 104 times

Online Publication Date: 7 October 2003

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The exact Green’s function of a heterogeneous medium can be retrieved from the crosscorrelation of the fields received by two passive sensors. We propose a physical interpretation based on time-reversal symmetry. We address the issue of causality and show the role of multiple scattering for the reconstruction of the Green’s function. Ultrasonic experimental results are presented to illustrate the argument. Applications to geophysics and ocean acoustics are discussed. © 2003 American Institute of Physics.
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43.25.Cb Macrosonic propagation, finite amplitude sound; shock waves
43.30.-k Underwater sound
92.10.Vz Underwater sound
93.85.-q Instruments and techniques for geophysical research: Exploration geophysics

Semiconducting nanocrystalline iron disilicide thin films prepared by pulsed-laser ablation

T. Yoshitake, M. Yatabe, M. Itakura, N. Kuwano, Y. Tomokiyo, and K. Nagayama

Appl. Phys. Lett. 83, 3057 (2003); http://dx.doi.org/10.1063/1.1617374 (3 pages) | Cited 14 times

Online Publication Date: 7 October 2003

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Amorphous iron silicide was reported to be semiconducting as well as β-FeSi2, and it has received considerable attention from both the physical and engineering points of view. However, there have been few studies and its basic properties are still unknown. We could grow the semiconducting nanocrystalline iron disilicide thin films by pulsed-laser deposition using an FeSi2 target. They consist of crystallites with diameters ranging from 3 to 5 nm. The carrier density and the mobility at 300 K were 1.5×1019 cm−3 and 35 cm/V s, respectively. © 2003 American Institute of Physics.
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68.55.-a Thin film structure and morphology
73.61.Le Other inorganic semiconductors
81.15.Fg Pulsed laser ablation deposition
73.50.Dn Low-field transport and mobility; piezoresistance

Room-temperature epitaxial growth of GaN on conductive substrates

J. Ohta, H. Fujioka, and M. Oshima

Appl. Phys. Lett. 83, 3060 (2003); http://dx.doi.org/10.1063/1.1617376 (3 pages) | Cited 30 times

Online Publication Date: 7 October 2003

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We have grown GaN films on (Mn,Zn)Fe2O4 (111) substrates by pulsed-laser deposition at room temperature and investigated their structural properties using reflection high-energy electron diffraction, atomic force microscopy, grazing-incidence x-ray reflectivity, and grazing-incidence x-ray diffraction (GIXD). We have found that GaN (0001) grows epitaxially even at room temperature. The room-temperature growth of GaN starts with the two-dimensional mode followed by the three-dimensional mode, which indicates that the precursors of GaN have large energy enough to migrate on the surface. GIXD measurements showed that the in-plane epitaxial relationship is GaN [11-20] // (Mn,Zn)Fe2O4 [01-1] and approximately 90% of the lattice mismatch is released at the interface. These results indicate that the present technique solves one of the two major problems with epitaxial growth of GaN (mismatch in the thermal expansion coefficients) and alleviates the other problem (mismatch in the lattice constants). © 2003 American Institute of Physics.
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81.05.Ea III-V semiconductors
81.15.Fg Pulsed laser ablation deposition
68.37.Ps Atomic force microscopy (AFM)
68.55.A- Nucleation and growth

Study of negative-bias temperature-instability-induced defects using first-principle approach

Jia Mei Soon, Kian Ping Loh, Shyue Seng Tan, T. P. Chen, W. Y. Teo, and L. Chan

Appl. Phys. Lett. 83, 3063 (2003); http://dx.doi.org/10.1063/1.1614415 (3 pages) | Cited 3 times

Online Publication Date: 7 October 2003

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In this letter, we report the study of negative-bias temperature-instability (NBTI)-induced defect using first-principle calculations. From our calculations, we found that the NBTI effect leads to an overall decrease in frontier molecular orbital energy gap at the interface. We studied the interface structure at an atomistic level and proposed an explanation for this phenomenon using molecular orbital theory and band theory. In addition, weakening of bond strength of Si–O at the defect site is observed. It is found that upon formation of a defect, an energy state is created inside the band gap of SiO2. These results improve our understanding of the consequences associated with the NBTI effect, and the self-propagating nature of the NBTI effect. © 2003 American Institute of Physics.
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73.20.At Surface states, band structure, electron density of states
73.20.Hb Impurity and defect levels; energy states of adsorbed species
71.15.-m Methods of electronic structure calculations

Effects of copolymer segment length and reversible deformation on the molecular surface structure of polyurethane

E. Amitay-Sadovsky, K. Komvopoulos, R. Ward, and G. A. Somorjai

Appl. Phys. Lett. 83, 3066 (2003); http://dx.doi.org/10.1063/1.1610249 (3 pages) | Cited 3 times

Online Publication Date: 7 October 2003

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The surface molecular structure and the deformation mechanisms of two polyurethane (PUR) short-segmented copolymers were studied by sum frequency generation (SFG) vibrational spectroscopy. These PURs differ only in the length of their hard segment. Surface deformation was induced by cyclically stretching the PUR films to a macroscopic elastic elongation. Results for both PUR compositions indicate that the upward orientation of the methylene groups increases with elongation and decreases upon relaxation. The surface of the stretched PUR films with shorter hard segments exhibited irreversible deformation at the molecular level. This produced a surface composition similar to that of PUR with longer hard segments that deformed only elastically after three stretching cycles. This behavior indicates that the surface structure of PUR copolymers can be controlled by mechanical manipulation or by modification of the copolymer segment length. © 2003 American Institute of Physics.
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68.35.B- Structure of clean surfaces (and surface reconstruction)
61.41.+e Polymers, elastomers, and plastics
62.20.F- Deformation and plasticity
81.40.Lm Deformation, plasticity, and creep
81.05.Lg Polymers and plastics; rubber; synthetic and natural fibers; organometallic and organic materials

Strain relaxation in stacked InAs/GaAs quantum dots studied by Raman scattering

J. Ibáñez, A. Patanè, M. Henini, L. Eaves, S. Hernández, R. Cuscó, L. Artús, Yu. G. Musikhin, and P. N. Brounkov

Appl. Phys. Lett. 83, 3069 (2003); http://dx.doi.org/10.1063/1.1618368 (3 pages) | Cited 17 times

Online Publication Date: 7 October 2003

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We report a Raman scattering investigation of InAs vibrational modes in multiple layers of InAs self-assembled quantum dots in a GaAs matrix. The Raman peak associated with quantum-dot phonons shows a downward frequency shift as the interlayer spacing decreases. We attribute this frequency shift to the relaxation of the elastic strain in the stacked quantum-dot layers. From the phonon frequency shift, we estimate the magnitude of the strain in the quantum dot layers, which we relate to the energy of the photoluminescence emission of the dots. © 2003 American Institute of Physics.
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68.65.Hb Quantum dots (patterned in quantum wells)
78.67.Hc Quantum dots
78.30.Fs III-V and II-VI semiconductors
63.22.-m Phonons or vibrational states in low-dimensional structures and nanoscale materials
78.55.Cr III-V semiconductors

Growth and characteristics of TaN/TiN superlattice structures

H. Wang, X. Zhang, A. Gupta, Ashutosh Tiwari, and J. Narayan

Appl. Phys. Lett. 83, 3072 (2003); http://dx.doi.org/10.1063/1.1616656 (3 pages) | Cited 2 times

Online Publication Date: 7 October 2003

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Epitaxial B1 NaCl-structured TaN(3 nm)/TiN(2 nm) superlattice structures were grown on Si(100) substrates with a TiN buffer layer, using pulsed-laser deposition. A special target assembly was used to manipulate the thickness of each layer. X-ray diffraction, transmission electron microscopy, and scanning transmission electron microscopy (Z contrast) studies confirmed the single-crystalline nature of the superlattice with a uniform layer structure. Nanoindentation results suggest the high hardness of these superlattice structures. Four-point-probe resistivity measurements show low resistivity of the heterostructures and a Cu diffusion characteristic study proved this superlattice system can be a promising diffusion barrier and can withstand 700 °C annealing for 30 min. © 2003 American Institute of Physics.
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68.65.Cd Superlattices
81.15.Fg Pulsed laser ablation deposition
81.16.Mk Laser-assisted deposition
68.35.Gy Mechanical properties; surface strains
62.20.M- Structural failure of materials
62.20.Qp Friction, tribology, and hardness
81.40.Np Fatigue, corrosion fatigue, embrittlement, cracking, fracture, and failure
61.72.Cc Kinetics of defect formation and annealing
68.35.Fx Diffusion; interface formation
73.61.Ng Insulators

Experimental and theoretical investigation on the structural properties of GaN grown on sapphire

J. Ohta, H. Fujioka, M. Oshima, K. Fujiwara, and A. Ishii

Appl. Phys. Lett. 83, 3075 (2003); http://dx.doi.org/10.1063/1.1618379 (3 pages) | Cited 27 times

Online Publication Date: 7 October 2003

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We have investigated the growth mechanisms of group-III nitrides on c-plane sapphire substrates with experiments by pulsed-laser deposition and first-principles calculations. It has been experimentally revealed that the in-plane alignment between the nitrides and sapphire is [10-10]nitride//[11-20]sapphire and the nitride films have the N polarity for the most cases. We have found that the insertion of an Al-rich AlN buffer layer effectively turns over the GaN crystals from the N polarity to the Ga polarity, although the Ga-rich GaN buffer layer does not cause change in the polarity. The theoretical energy calculations of a sapphire slab with an adatom explain the experimental results, such as the in-plane alignment and the polarity change, quite well. © 2003 American Institute of Physics.
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68.55.-a Thin film structure and morphology
68.35.Md Surface thermodynamics, surface energies

Room-temperature preparation of β-FeSi2 microprecipitates by the KrF excimer laser ablation of an iron disilicide alloy target

Aiko Narazaki, Tadatake Sato, Yoshizo Kawaguchi, and Hiroyuki Niino

Appl. Phys. Lett. 83, 3078 (2003); http://dx.doi.org/10.1063/1.1618019 (3 pages) | Cited 4 times

Online Publication Date: 7 October 2003

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We have fabricated β-FeSi2 microprecipitates at room temperature using KrF excimer laser ablation of an α-FeSi2 alloy target. Raman spectra with a spatial resolution of 1 μm confirmed that the micron-sized droplets generated by laser ablation precipitate as the β-FeSi2 crystalline phase on a silicon substrate maintained at RT, whereas the rest of the deposited film is amorphous. It was also found that films containing a high density of β-FeSi2 precipitates exhibited 1.55 μm photoluminescence at low temperature (up to 200 K) after annealing at 800 °C for 6 h in an argon atmosphere. © 2003 American Institute of Physics.
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81.15.Fg Pulsed laser ablation deposition
68.55.-a Thin film structure and morphology
64.75.-g Phase equilibria
61.72.Cc Kinetics of defect formation and annealing
78.55.Hx Other solid inorganic materials
78.30.Hv Other nonmetallic inorganics
78.66.Li Other semiconductors

Ultrathin single-crystalline-silicon cantilever resonators: Fabrication technology and significant specimen size effect on Young’s modulus

Xinxin Li, Takahito Ono, Yuelin Wang, and Masayoshi Esashi

Appl. Phys. Lett. 83, 3081 (2003); http://dx.doi.org/10.1063/1.1618369 (3 pages) | Cited 115 times

Online Publication Date: 7 October 2003

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Ultrathin resonant cantilevers are promising for ultrasensitive detection. A technique is developed for high-yield fabrication of single-crystalline-silicon cantilevers as thin as 12 nm. The formed cantilever resonators are characterized by resonance testing in high vacuum. Significant specimen size effect on Young’s modulus of ultrathin (12–170 nm) silicon is detected. The Young’s modulus decreases monotonously as the cantilevers become thinner. The size effect is consistent with the published simulation results of direct-atomistic model, in which surface effects are taken into consideration. © 2003 American Institute of Physics.
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07.10.Cm Micromechanical devices and systems
85.85.+j Micro- and nano-electromechanical systems (MEMS/NEMS) and devices
81.05.Cy Elemental semiconductors
62.25.-g Mechanical properties of nanoscale systems
62.20.D- Elasticity
81.16.-c Methods of micro- and nanofabrication and processing
61.46.-w Structure of nanoscale materials
81.07.Bc Nanocrystalline materials

Room-temperature light emission from a highly strained Si/Ge superlattice

N. D. Zakharov, V. G. Talalaev, P. Werner, A. A. Tonkikh, and G. E. Cirlin

Appl. Phys. Lett. 83, 3084 (2003); http://dx.doi.org/10.1063/1.1618377 (3 pages) | Cited 25 times

Online Publication Date: 7 October 2003

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We discuss the formation of a Si/Ge-superlattice (SL) generated by molecular beam epitaxy. Specific growth parameter were chosen to optimize the periodic structure of vertically stacked Ge islands. Optimized SLs show a strong photoluminescence at a wavelength in the region of 1.55 μm up to room temperature. The luminescence is explained by a recombination of electrons in a miniband and holes localized in the Ge islands. The morphology and the crystal structure of the SL, which are influenced by the growth parameters, were analyzed by transmission electron microscopy techniques. It is demonstrated that doping of the SL structure by antimony improves both structural and optical properties. © 2003 American Institute of Physics.
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78.67.Pt Multilayers; superlattices; photonic structures; metamaterials
68.65.Cd Superlattices
78.55.Ap Elemental semiconductors
68.37.Lp Transmission electron microscopy (TEM)

Observation of huge nonlinear absorption enhancement near exciton resonance in GaN

Kung-Hsuan Lin, Gia-Wei Chern, Yin-Chieh Huang, Stacia Keller, Steven P. DenBaars, and Chi-Kuang Sun

Appl. Phys. Lett. 83, 3087 (2003); http://dx.doi.org/10.1063/1.1619218 (3 pages) | Cited 9 times

Online Publication Date: 7 October 2003

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Huge excitonic enhancement of two-photon absorption near the exciton-transition energy was observed in the GaN system. The peak value of the nonlinear absorption coefficient is at least 1500 cm/GW, corresponding to an enhancement factor of >100. The room temperature exciton dephasing time is also obtained based on a spectral analysis to be ∼150 fs in bulk GaN, which is close to the exciton ionization time. © 2003 American Institute of Physics.
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78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
71.35.Cc Intrinsic properties of excitons; optical absorption spectra

Frequency converters from visible to mid-infrared with periodically poled RbTiOPO4

A. Fragemann, V. Pasiskevicius, J. Nordborg, J. Hellström, H. Karlsson, and F. Laurell

Appl. Phys. Lett. 83, 3090 (2003); http://dx.doi.org/10.1063/1.1619211 (3 pages) | Cited 3 times

Online Publication Date: 7 October 2003

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Electric-field poling has been used to fabricate quasi-phase-matched frequency converters in RbTiOPO4. A more accurate Sellmeier equation has been obtained for wavelengths between 0.43 and 3.4 μm. The dispersion of the thermo-optic coefficient for nz refractive index has been derived in the near- to mid-infrared spectral region. The nonlinear performance of periodically poled RbTiOPO4 obtained in the infrared optical parametric devices is comparable to that of periodically poled KTiOPO4. © 2003 American Institute of Physics.
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42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials
78.20.N- Thermo-optic effects
78.20.nb Photothermal effects
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)

Role of nanometer-scale quasicrystals in improving the mechanical behavior of Ti-based bulk metallic glasses

Yu Chan Kim, Jong Hyun Na, Jin Man Park, Do Hyang Kim, Jin Kyu Lee, and Won Tae Kim

Appl. Phys. Lett. 83, 3093 (2003); http://dx.doi.org/10.1063/1.1616198 (3 pages) | Cited 72 times

Online Publication Date: 7 October 2003

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The effect of the precipitation of nanosized quasicrystals on the mechanical properties of Ti–Zr–Cu–Ni–Be bulk metallic glasses (BMG) has been investigated. The Ti40Zr29Cu8Ni7Be16 BMG crystallizes by forming a few nanometer-size quasicrystals in the amorphous matrix, enabling the fabrication of quasicrystal-reinforced BMG matrix composites. Simultaneous improvement of strength and ductility can be obtained when 3–5-nm-size quasicrystals are isolated and homogeneously distributed in an amorphous matrix. The fracture strength and global strain, respectively, increase from 1921 MPa and 5.1% for as-cast BMG to 2084 MPa and 6.2% for partially crystallized BMG with the volume fraction of ∼ 7% quasicrystals. These improvements may be attributed to the structural similarity between quasicrystalline and amorphous phases. Stable low-energy interface between two phases may act as a source for multiple-shear-band formation. © 2003 American Institute of Physics.
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62.25.-g Mechanical properties of nanoscale systems
61.44.Br Quasicrystals
61.43.Fs Glasses
62.20.F- Deformation and plasticity

β-phase tungsten nanorod formation by oblique-angle sputter deposition

Tansel Karabacak, Anupama Mallikarjunan, Jitendra P. Singh, Dexian Ye, Gwo-Ching Wang, and Toh-Ming Lu

Appl. Phys. Lett. 83, 3096 (2003); http://dx.doi.org/10.1063/1.1618944 (3 pages) | Cited 47 times

Online Publication Date: 7 October 2003

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We report the creation of an unusual simple cubic β-phase W(100) nanorods with a pyramidal tip having four (110) facets using an oblique-angle sputter deposition technique with substrate rotation (also known as glancing-angle deposition). During the oblique-angle deposition, both β-phase W(100) and α-phase W(110) islands exist at the initial stages of growth. The β-phase W(100) islands grow taller due to the lower adatom mobility on these islands. The taller islands survive in the competition and form isolated nanorods in the later stages of growth. This is in contrast to the sputter deposition at normal incidence, where only the thermodynamically stable bcc α-phase W(110) polycrystalline films were formed when the film grows to a certain thickness. © 2003 American Institute of Physics.
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68.55.Nq Composition and phase identification
81.15.Cd Deposition by sputtering
61.46.-w Structure of nanoscale materials
81.07.Bc Nanocrystalline materials

Thermal expansion coefficient of hydrogenated amorphous carbon

F. C. Marques, R. G. Lacerda, A. Champi, V. Stolojan, D. C. Cox, and S. R. P. Silva

Appl. Phys. Lett. 83, 3099 (2003); http://dx.doi.org/10.1063/1.1619557 (3 pages) | Cited 30 times

Online Publication Date: 7 October 2003

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The coefficient of thermal expansion (CTE) of hydrogenated amorphous carbon (a-C:H) was investigated as a function of the concentration of sp2 hybridization. The CTE, determined using the thermally induced bending technique, depends on the concentration of sp2 bonded carbon, increasing to the value of graphite as the sp2 concentration approaches 100%. By using a combination of the thermally induced bending technique and nanohardness measurements, we extract separately the Young’s modulus and Poisson’s ratio of the a-C:H films as function of the sp2 concentration. © 2003 American Institute of Physics.
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65.60.+a Thermal properties of amorphous solids and glasses: heat capacity, thermal expansion, etc.
62.20.D- Elasticity
62.20.Qp Friction, tribology, and hardness
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