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1 Aug 2011

Volume 99, Issue 5, Articles (05xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 99, 051112 (2011); http://dx.doi.org/10.1063/1.3617421 (3 pages)

Wei Li, Jun Chen, Gerard Nouet, Liang-yao Chen, and Xunya Jiang
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O-band excited state quantum dot bilayer lasers

M. A. Majid, D.T.D. Childs, K. Kennedy, R. Airey, R. A. Hogg, E. Clarke, P. Spencer, and R. Murray

Appl. Phys. Lett. 99, 051101 (2011); http://dx.doi.org/10.1063/1.3605590 (3 pages) | Cited 1 time

Online Publication Date: 1 August 2011

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Bilayer InAs/GaAs quantum dot (QD) lasers operating in the excited state at wavelengths that span the O-band are demonstrated. The higher saturated gain and lower scattering time of the excited states of the ensemble of QDs offers the opportunity for fast direct-modulation lasers. We predict an increase in K-factor limited modulation bandwidth from QD lasers operating in the excited state due to a reduction in carrier transport and scattering times whilst maintaining high peak modal gain.
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42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems
68.47.Fg Semiconductor surfaces
42.60.Fc Modulation, tuning, and mode locking

Room temperature spin relaxation length in spin light-emitting diodes

Henning Soldat, Mingyuan Li, Nils C. Gerhardt, Martin R. Hofmann, Arne Ludwig, Astrid Ebbing, Dirk Reuter, Andreas D. Wieck, Frank Stromberg, Werner Keune, and Heiko Wende

Appl. Phys. Lett. 99, 051102 (2011); http://dx.doi.org/10.1063/1.3622662 (3 pages) | Cited 8 times

Online Publication Date: 2 August 2011

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We investigate the spin relaxation length in GaAs spin light-emitting diode devices under drift transport at room temperature. The spin-polarised electrons are injected through a MgO tunnel barrier from a Fe/Tb multilayer in magnetic remanence. The decrease in circular polarization with increasing injection path length is investigated and found to be exponential, supporting drift-based transport. The spin relaxation length in our samples is 26 nm, and a lower bound for the spin injection efficiency at the spin injector/GaAs interface is estimated to be 25 ± 2%.
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85.60.Jb Light-emitting devices
75.76.+j Spin transport effects
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
72.25.-b Spin polarized transport

On the optical polarization properties of semipolar InGaN quantum wells

L. Schade, U. T. Schwarz, T. Wernicke, J. Rass, S. Ploch, M. Weyers, and M. Kneissl

Appl. Phys. Lett. 99, 051103 (2011); http://dx.doi.org/10.1063/1.3618676 (3 pages) | Cited 7 times

Online Publication Date: 2 August 2011

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Polarized photoluminescence of strained quantum wells grown on c–plane, semipolar (10math2), (11math2), (10math1), (20math1) planes, and nonpolar GaN substrates was studied experimentally and in theory. The observed optical polarization switching between the substrate orientations (10math2) and (11math2) is in accordance with our general model of polarization switching, based on a math·math model of arbitrary substrate orientation. Spectrally resolved measurements of the polarization degree stemming from (10math2) samples show that the maximum of the polarization degree is red–shifted with respect to the maximum of the photoluminescence intensity. We ascribe this effect to an increased polarization of the transitions for higher indium content.
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78.66.Fd III-V semiconductors
78.67.De Quantum wells
78.55.Cr III-V semiconductors

1 × 12 Unequally spaced waveguide array for actively tuned optical phased array on a silicon nanomembrane

David Kwong, Amir Hosseini, Yang Zhang, and Ray T. Chen

Appl. Phys. Lett. 99, 051104 (2011); http://dx.doi.org/10.1063/1.3619847 (3 pages) | Cited 5 times

Online Publication Date: 2 August 2011

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We present an experimental demonstration of an optical phased array implementation on silicon nanomembrane. The integrated on-chip array configuration is non-uniform and avoids grating lobes inside the field of view during beam steering while allowing the waveguide separation to be large enough to prevent optical coupling. A 1 × 12 multimode interference beam splitter uniformly excites the arrayed waveguides. Individually controllable micro-heaters modulate the optical phase in the arrayed waveguides. A beam steering angle of 10.2° in a silicon planar guide equivalent to an effective steering angle of 31.9° in air is demonstrated at 1.55 μm.
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42.79.Gn Optical waveguides and couplers
42.82.-m Integrated optics

A microfiber cavity with minimal-volume confinement

Ming Ding, Pengfei Wang, Timothy Lee, and Gilberto Brambilla

Appl. Phys. Lett. 99, 051105 (2011); http://dx.doi.org/10.1063/1.3621836 (3 pages) | Cited 6 times

Online Publication Date: 2 August 2011

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We demonstrate a type of microcavity with minimal-volume confinement using a high-contrast phase-shifted Bragg grating in a microfiber. While waveguiding by the air-silica boundary provides a diffraction-limited two-dimensional confinement, the grating introduces the third degree of confinement. Theoretical simulations verified the microfiber cavity confinement while the experimental demonstration, carried out in samples nanostructured by focused ion beam, showed a good agreement with theoretical predictions. This cavity can be used for a variety of applications ranging from sensing to quantum dynamic experiments.
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42.81.Wg Other fiber-optical devices
42.65.-k Nonlinear optics
42.79.Dj Gratings

Backward growth of plasma induced by long nanosecond laser pulse ablation

Yun Zhou, Sha Tao, and Benxin Wu

Appl. Phys. Lett. 99, 051106 (2011); http://dx.doi.org/10.1063/1.3621855 (3 pages) | Cited 3 times

Online Publication Date: 2 August 2011

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An interesting physical phenomenon of laser-induced plasma backward growth has been found for long nanosecond (ns) laser pulse ablation, which has been rarely reported. Time-resolved observation shows that the plasma bottom appears to be detached from the ablated target surface shortly after laser pulse ends, and then the bottom grows backwards towards the target. This phenomenon is understood through an experimentally verified, physics-based model. The study shows that the plasma backward growth is fundamentally the backward growth of high-temperature region bottom boundary without any significant backward motion of material, and the underlying gas dynamic process has also been revealed.
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52.50.Jm Plasma production and heating by laser beams (laser-foil, laser-cluster, etc.)
52.70.Kz Optical (ultraviolet, visible, infrared) measurements
52.38.Mf Laser ablation

Ultralow power all-optical diode in photonic crystal heterostructures with broken spatial inversion symmetry

Cuicui Lu, Xiaoyong Hu, Yingbo Zhang, Zhiqiang Li, Xin’an Xu, Hong Yang, and Qihuang Gong

Appl. Phys. Lett. 99, 051107 (2011); http://dx.doi.org/10.1063/1.3617433 (3 pages) | Cited 7 times

Online Publication Date: 3 August 2011

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We experimentally realize an all-optical diode in a photonic crystal heterostructure with broken spatial inversion symmetry. The physical mechanism is attributed to bandgaps only for certain wavevectors and the transition between different electromagnetic Bloch modes, without any nonlinearity and high power requirement. An ultralow photon intensity of 50 kW/cm2 and an ultrahigh transmission contrast of over 103 are reached simultaneously. Compared with previous reported all-optical diodes, the operating power is reduced by seven orders of magnitude, while the transmission contrast is enlarged by two orders of magnitude. This approach may open a way for the study of integrated photonic devices.
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42.70.Qs Photonic bandgap materials
85.60.Dw Photodiodes; phototransistors; photoresistors

Subwavelength lateral confinement of microwave surface waves

Elizabeth M. G. Brock, Euan Hendry, and Alastair P. Hibbins

Appl. Phys. Lett. 99, 051108 (2011); http://dx.doi.org/10.1063/1.3622646 (3 pages) | Cited 6 times

Online Publication Date: 3 August 2011

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Experimental verification of the “domino plasmon,” recently proposed by Cano et al. [Opt. Express 18(2), 754, (2010)] is presented. Using microwaves, it is demonstrated that this mode propagates along a periodic chain of metallic cuboids (“dominos”) and the dispersion of the mode is determined with results being compared to the predictions of analytical and numerical models. This mode is found to be surprisingly insensitive to the lateral width of the chain, even on a subwavelength scale. Having such tight confinement, “domino plasmons” show considerable promise for one-dimensional subwavelength guiding and focusing of electromagnetic fields.
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84.40.Az Waveguides, transmission lines, striplines
41.20.Jb Electromagnetic wave propagation; radiowave propagation
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)

High optical polarization ratio from semipolar (20mathmath) blue-green InGaN/GaN light-emitting diodes

Yuji Zhao, Shinichi Tanaka, Qimin Yan, Chia-Yen Huang, Roy B. Chung, Chih-Chien Pan, Kenji Fujito, Daniel Feezell, Chris G. Van de Walle, James S. Speck, Steven P. DenBaars, and Shuji Nakamura

Appl. Phys. Lett. 99, 051109 (2011); http://dx.doi.org/10.1063/1.3619826 (3 pages) | Cited 6 times

Online Publication Date: 3 August 2011

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The optical polarization ratio of spontaneous emission was investigated by electroluminescence measurements for semipolar (20mathmath) InGaN/GaN light-emitting diodes, covering the blue to green spectral range. Devices fabricated on semipolar (20mathmath) substrates exhibit polarization ratios ranging from 0.46 at 418 nm to 0.67 at 519 nm. These polarization ratios are significantly higher than those reported on semipolar (20math1) devices. The valence band energy separation is extracted from spectral measurements and is consistent with the increased polarization ratio and theoretical predictions. Quantum well interdiffusion induced valence band mixing is suggested as a possible explanation for the low experimental value of polarization ratio observed for the (20math1) devices.
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85.60.Jb Light-emitting devices

Strong coupling between surface plasmon polariton and laser dye rhodamine 800

Federico Valmorra, Markus Bröll, Stephan Schwaiger, Nadine Welzel, Detlef Heitmann, and Stefan Mendach

Appl. Phys. Lett. 99, 051110 (2011); http://dx.doi.org/10.1063/1.3619845 (3 pages) | Cited 1 time

Online Publication Date: 3 August 2011

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We report on strong coupling between surface plasmon polaritons on a thin silver film and laser dye Rhodamine 800. Attenuated total reflection measurements reveal that the pure surface plasmon polaritons interact with the Rhodamine 800 absorption lines exhibiting pronounced anticrossings in the dispersion relation. We show that the corresponding energy gap can be tailored by the concentration of dye molecules in the dielectric matrix between 50 meV and 70 meV. We can well model our data by a classical transfer matrix approach as well as by a quantum mechanical coupled oscillator ansatz.
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73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)
78.40.Kc Metals, semimetals, and alloys
78.66.Bz Metals and metallic alloys
71.36.+c Polaritons (including photon-phonon and photon-magnon interactions)

Angular emission properties of a layer of rare-earth based nanophosphors embedded in one-dimensional photonic crystal coatings

O. Sánchez-Sobrado, A. M. Yacomotti, M. E. Calvo, O. E. Martínez, M. Ocaña, N. Núñez, J. A. Levenson, and H. Míguez

Appl. Phys. Lett. 99, 051111 (2011); http://dx.doi.org/10.1063/1.3619814 (3 pages) | Cited 1 time

Online Publication Date: 4 August 2011

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The angular properties of light emitted from rare-earth based nanophosphors embedded in optical resonators built in one-dimensional photonic crystal coatings are herein investigated. Strong directional dependence of the photoluminescence spectra is found. Abrupt angular variations of the enhancement caused by the photonic structure and the extraction power are observed, in good agreement with calculated polar emission patterns. Our results confirm that the optical cavity favors the extraction of different wavelengths at different angles and that integration of nanophosphors within photonic crystals provides control over the directional emission properties that could be put into practice in phosphorescent displays.
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42.70.Qs Photonic bandgap materials
42.79.Wc Optical coatings
78.55.Hx Other solid inorganic materials
42.55.Tv Photonic crystal lasers and coherent effects

The methods to detect vacuum polarization by evanescent modes

Wei Li, Jun Chen, Gerard Nouet, Liang-yao Chen, and Xunya Jiang

Appl. Phys. Lett. 99, 051112 (2011); http://dx.doi.org/10.1063/1.3617421 (3 pages) | Cited 2 times

Online Publication Date: 4 August 2011

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We propose the evanescent-mode-sensing methods to probe the quantum electrodynamics (QED) vacuum polarization. From our methods, high-sensitivity can be achieved even though the external field is much smaller than the Schwinger critical field and may be realizable in contemporary experimental conditions. The methods are based on the effect of phase change and time delay of evanescent wave which is transmitted in QED vacuum.
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42.81.Pa Sensors, gyros

Solid-state optimal phase-covariant quantum cloning machine

Xin-Yu Pan, Gang-Qin Liu, Li-Li Yang, and Heng Fan

Appl. Phys. Lett. 99, 051113 (2011); http://dx.doi.org/10.1063/1.3624595 (3 pages) | Cited 5 times

Online Publication Date: 5 August 2011

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Here, we report an experimental realization of optimal phase-covariant quantum cloning machine with a single electron spin in solid state system at room temperature. The involved three states of two logic qubits are encoded physically in three levels of a single electron spin with two Zeeman sub-levels at a nitrogen-vacancy defect center in diamond. The preparation of input state and the phase-covariant quantum cloning transformation is controlled by two independent microwave fields. The average experimental fidelity reaches 85.2% which is very close to theoretical optimal fidelity 85.4% and is beyond the bound 83.3% of universal cloning.
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03.67.Ac Quantum algorithms, protocols, and simulations
03.67.Lx Quantum computation architectures and implementations
61.72.jd Vacancies
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MeV negative ion generation from ultra-intense laser interaction with a water spray

S. Ter-Avetisyan, B. Ramakrishna, M. Borghesi, D. Doria, M. Zepf, G. Sarri, L. Ehrentraut, A. Andreev, P. V. Nickles, S. Steinke, W. Sandner, M. Schnürer, and V. Tikhonchuk

Appl. Phys. Lett. 99, 051501 (2011); http://dx.doi.org/10.1063/1.3622664 (3 pages) | Cited 8 times

Online Publication Date: 5 August 2011

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MeV negative oxygen ions are obtained from a water spray target irradiated by high intensity (5 × 1019 W/cm2) and ultrashort (50 fs) laser pulses. Generation of negative ions is ascribed to electron-capture processes that the laser-accelerated high-energy positive ion experiences when it interacts with atoms in the spray. This mechanism implies the existence of a large number of MeV neutral oxygen atoms, which is consistent with indirect experimental evidence.
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07.77.Ka Charged-particle beam sources and detectors
33.80.Eh Autoionization, photoionization, and photodetachment
33.80.Gj Diffuse spectra; predissociation, photodissociation
34.70.+e Charge transfer
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Highest transmittance and high-mobility amorphous indium gallium zinc oxide films on flexible substrate by room-temperature deposition and post-deposition anneals

Mandar J. Gadre and T. L. Alford

Appl. Phys. Lett. 99, 051901 (2011); http://dx.doi.org/10.1063/1.3619196 (3 pages) | Cited 3 times

Online Publication Date: 1 August 2011

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Amorphous indium gallium zinc oxide (a-IGZO) thin films of the highest transmittance reported in literature were initially deposited onto flexible polymer substrates at room temperature. The films were annealed in vacuum, air, and oxygen to enhance their electrical and optical performances. Electrical and optical characterizations were done before and after anneals. A partial reversal of the degradation in electrical properties upon annealing in oxygen was achieved by subjecting the films to subsequent vacuum anneals. A model was developed based on film texture and structural defects which showed close agreement between the measured and calculated carrier mobility values at low carrier concentrations (2–6 × 1019 cm−3).
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73.61.Jc Amorphous semiconductors; glasses
78.66.Hf II-VI semiconductors
78.66.Jg Amorphous semiconductors; glasses
81.15.Cd Deposition by sputtering
72.20.Fr Low-field transport and mobility; piezoresistance
73.61.Ga II-VI semiconductors

Collateral evidence for an excellent radiative performance of AlxGa1−xN alloy films of high AlN mole fractions

S. F. Chichibu, K. Hazu, T. Onuma, and A. Uedono

Appl. Phys. Lett. 99, 051902 (2011); http://dx.doi.org/10.1063/1.3615681 (3 pages) | Cited 4 times

Online Publication Date: 1 August 2011

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Recombination dynamics for the deep-ultraviolet (DUV) near-band-edge emission of AlxGa1−xN epilayers of high AlN mole fractions (x) are studied using time-resolved spectroscopy. Their low-temperature radiative lifetime (τR) is longer than that for the epilayers of low-x AlxGa1−xN, AlN, or GaN due to the contribution of bound and localized tail-states. However, τR shows little change with temperature rise, and the value is a few ns at 300 K. The results essentially indicate an excellent radiative performance of AlxGa1−xN alloys of high x, although the luminescence efficiency of AlxGa1−xN DUV light-emitting-diodes reported so far is limited by the short nonradiative lifetime.
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78.66.Fd III-V semiconductors
78.47.jd Time resolved luminescence
78.60.Hk Cathodoluminescence, ionoluminescence
78.55.Cr III-V semiconductors
78.70.Bj Positron annihilation

Photo-induced lattice softening of excited-state VO2

Masaki Hada, Kunio Okimura, and Jiro Matsuo

Appl. Phys. Lett. 99, 051903 (2011); http://dx.doi.org/10.1063/1.3621900 (3 pages) | Cited 7 times

Online Publication Date: 1 August 2011

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In this letter, we demonstrated the photoexcitation of metallic phase vanadium dioxide (VO2) with time-resolved x-ray diffraction measurements. Through the photoexcitation, the metallic phase VO2 transitioned to the similar transient state, which was presented in the insulator to metal phase transition in the time-scale of ∼10 ps. This transient state was accessed only by the photoexcitation and not through further thermal excitation. The presence of the transient state could be an important factor in any further application of the phase transition phenomena.
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72.60.+g Mixed conductivity and conductivity transitions
81.30.Hd Constant-composition solid-solid phase transformations: polymorphic, massive, and order-disorder
64.70.K- Solid-solid transitions

Highly conductive and transparent alumina-doped ZnO films processed by direct pulsed laser recrystallization at room temperature

Martin Y. Zhang and Gary J. Cheng

Appl. Phys. Lett. 99, 051904 (2011); http://dx.doi.org/10.1063/1.3622645 (3 pages) | Cited 7 times

Online Publication Date: 2 August 2011

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Highly conductive and transparent alumina-doped ZnO (AZO) thin films (250 nm) are deposited at room temperature using pulsed laser deposition (PLD) and direct pulsed laser recrystallization (DPLR). Morphological characterizations show that the AZO films undergo recrystallization and growth during DPLR, which leads to less internal imperfections in AZO films and hence better film conductance. Electrical-optical characterizations show that DPLR results in significant improvement in conductivity, Hall mobility, and transmission from UV to NIR regions. Decrease in carrier concentration density in AZO film is observed. Compared with PLD, DPLR processed AZO films also possess smaller band gap which leads to broader solar spectrum acceptance.
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68.55.ag Semiconductors
73.61.Ey III-V semiconductors
78.66.Fd III-V semiconductors
81.05.Dz II-VI semiconductors
81.15.Fg Pulsed laser ablation deposition
61.72.uj III-V and II-VI semiconductors

Stress changed damping and associated transforming behavior in a Ti48.5Ni51.5 strain glass

Yu Wang, Xiaoping Song, Xiangdong Ding, Sen Yang, Jian Zhang, Xiaobing Ren, and Kazuhiro Otsuka

Appl. Phys. Lett. 99, 051905 (2011); http://dx.doi.org/10.1063/1.3619830 (3 pages) | Cited 2 times

Online Publication Date: 2 August 2011

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We report a changeable damping behavior by stress for Ti48.5Ni51.5 strain glass. This phenomenon originates from the change of its transforming route upon increasing stress. Under low stress, the damping behavior of Ti48.5Ni51.5 strain glass is due to the strain glass transition; however, the damping behavior under intermediate stress stems from a strain glass transition and a subsequent martensitic transition. More interestingly, under high stress, the damping behavior is caused by the martensitic transition. With a phenomenological model, the stress dependent transforming behavior of strain glass can be explained consistently.
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61.43.Fs Glasses
62.40.+i Anelasticity, internal friction, stress relaxation, and mechanical resonances
81.05.Kf Glasses (including metallic glasses)
81.30.Kf Martensitic transformations
64.70.kj Glasses
64.70.pe Metallic glasses

Photoinduced mass-transport based holographic recording of surface relief gratings in amorphous selenium films

M. L. Trunov, P. M. Lytvyn, S. N. Yannopoulos, I. A. Szabo, and S. Kökényesi

Appl. Phys. Lett. 99, 051906 (2011); http://dx.doi.org/10.1063/1.3614432 (3 pages) | Cited 3 times

Online Publication Date: 2 August 2011

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Surface relief gratings formation in amorphous selenium thin films in two recording configurations with light intensity modulation were studied in situ by real-time atomic force microscopy and diffraction efficiency measurements. We report observation of mass transport effect in films induced by band-gap irradiation when the light polarization of the recording beams has a component along the light intensity gradient (“p-p” scheme of recording) that allows obtaining giant stable gratings in this versatile chalcogenide material. On the contrary, only a pure scalar weak grating caused by photoinduced volume shrinkage is obtained in the “s-s” recording configuration, even for long-term irradiation.
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42.79.Wc Optical coatings
78.66.Jg Amorphous semiconductors; glasses
78.20.hb Piezo-optical, elasto-optical, acousto-optical, and photoelastic effects
42.40.Ht Hologram recording and readout methods
42.40.My Applications
42.79.Dj Gratings

High frequency elastic losses in LaAlO3 and its importance for LaAlO3/SrTiO3 heterojunctions

Ekhard K. H. Salje and Michael A. Carpenter

Appl. Phys. Lett. 99, 051907 (2011); http://dx.doi.org/10.1063/1.3622305 (3 pages) | Cited 6 times

Online Publication Date: 2 August 2011

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Cooling heterojunctions on LaAlO3 substrates or thick layers of LaAlO3 on SrTiO3 substrates below 820 K lead to a ferroelastic phase transition Pmmathm→ Rmathc in LaAlO3, with extensive twinning and elastic softening. Twin boundaries add to structural disorder near the heterojunction and generate partially localized carriers. Resonant Ultrasound Spectroscopy data relating to the elastic instability in LaAlO3 show that elastic Cole-Cole circles and the background autocorrelation function follow Vogel-Fulcher behaviour, with a Vogel-Fulcher temperature of 230 K. An extremely low activation energy, 0.02 eV, would promote the formation of highly structured, “glassy” LaAlO3 near the junction.
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81.40.Jj Elasticity and anelasticity, stress-strain relations
81.70.Cv Nondestructive testing: ultrasonic testing, photoacoustic testing
62.20.dq Other elastic constants
64.70.K- Solid-solid transitions
61.72.Mm Grain and twin boundaries

Acoustic guiding and subwavelength imaging with sharp bending by sonic crystal

Bo Li, Ke Deng, and Heping Zhao

Appl. Phys. Lett. 99, 051908 (2011); http://dx.doi.org/10.1063/1.3622652 (3 pages) | Cited 2 times

Online Publication Date: 3 August 2011

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A sharp bending scheme for the self-collimation of acoustic waves is proposed by simply truncating the sonic crystals. An all-angle and wide-band 90°-bending wave guide is demonstrated with nearly perfect transmissions for Gaussian beams at a wide range of incident angles. A 90°-bended imaging for a point source with a subwavelength resolution of 0.37 λ0 is also realized by the proposed structure. These results will find applicability in the manipulation of acoustic waves by sonic crystals.
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42.79.Gn Optical waveguides and couplers
42.82.Et Waveguides, couplers, and arrays
43.20.-f General linear acoustics
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation
42.79.Ag Apertures, collimators

Mo- and N-doped BiNbO4 for photocatalysis applications

J. Nisar, B. C. Wang, B. Pathak, T. W. Kang, and R. Ahuja

Appl. Phys. Lett. 99, 051909 (2011); http://dx.doi.org/10.1063/1.3622659 (3 pages) | Cited 12 times

Online Publication Date: 3 August 2011

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The electronic structure of pure BiNbO4 has been calculated and their electronic band positions have been aligned with respect to the water oxidation/reduction potential. The effect of cationic (Mo), anionic (N), and co-doping (Mo-N) on BiNbO4 has been studied and discussed with respect to the standard redox potential levels. Our results show that co-doping of Mo and N in BiNbO4 reduces the band gap up to 31.8%, thus making it a potential candidate for the photocatalysis of water for hydrogen production. The relative stability between the mono- and co-doped BiNbO4 materials show that co-doped material is more stable and feasible in comparison to the mono-doped materials.
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71.20.Ps Other inorganic compounds
61.72.up Other materials

73 mm-diameter bulk metallic glass rod by copper mould casting

H. B. Lou, X. D. Wang, F. Xu, S. Q. Ding, Q. P. Cao, K. Hono, and J. Z. Jiang

Appl. Phys. Lett. 99, 051910 (2011); http://dx.doi.org/10.1063/1.3621862 (3 pages) | Cited 6 times

Online Publication Date: 3 August 2011

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To be structural materials, the critical size is always a bottleneck of bulk metallic glasses (BMGs) due to the cooling rate restriction. Here, we report a developed alloy of Zr46Cu30.14Ag8.36Al8Be7.5, which can be cast into amorphous rods in 73 mm diameter by copper mould casting. The strong glass forming ability of this alloy is closely related to the Be addition, which not only suppresses the phase separation happening in the as-cast Be-free BMG but also sustains low Gibbs free energy difference for crystallization. This finding will stimulate more interests in developing BMGs and their industrial applications.
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81.05.Kf Glasses (including metallic glasses)
64.70.kj Glasses
64.70.pe Metallic glasses
61.43.Fs Glasses
65.60.+a Thermal properties of amorphous solids and glasses: heat capacity, thermal expansion, etc.

Three dimensional distributions of arsenic and platinum within NiSi contact and gate of an n-type transistor

F. Panciera, K. Hoummada, M. Gregoire, M. Juhel, N. Bicais, and D. Mangelinck

Appl. Phys. Lett. 99, 051911 (2011); http://dx.doi.org/10.1063/1.3616150 (3 pages) | Cited 9 times

Online Publication Date: 3 August 2011

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Atom probe tomography was used to study the redistribution of platinum and arsenic atoms after Ni(Pt) silicidation of As-doped polycrystalline Si. These measurements were performed on a field-effect transistor and compared with those obtained in unpatterned region submitted to the same process. These results suggest that Pt and As redistribution during silicide formation is only marginally influenced by the confinement in microelectronic devices. On the contrary, there is a clear difference with the redistribution reported in the literature for the blanket wafers. Selective etching used to remove the non-reacted Ni(Pt) film after the first rapid heat treatment may induce this difference.
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85.30.Tv Field effect devices
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