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

12 Mar 2007

Volume 90, Issue 11, Articles (11xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 90, 113108 (2007); http://dx.doi.org/10.1063/1.2714186 (3 pages)

Samuel L. Mensah, Vijaya K. Kayastha, Ilia N. Ivanov, David B. Geohegan, and Yoke Khin Yap
Enlarge Image | Read More
Page 2 of 5 Pages Previous Page Next Page | Jump to Page
back to top
RSS Feeds

Evaluation of the thermal stability of Nd60Al20Co20 bulk metallic glass

L. Xia, D. Ding, S. T. Shan, and Y. D. Dong

Appl. Phys. Lett. 90, 111903 (2007); http://dx.doi.org/10.1063/1.2713179 (3 pages) | Cited 11 times

Online Publication Date: 12 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Long-term thermal stability of Nd60Al20Co20 bulk metallic glass (BMG) with excellent glass forming ability was investigated by Kissinger and Vogel-Fulcher-Tammann (VFT) analyses, respectively. The heating rate dependence of crystallization temperature of the BMG was found to follow the VFT nonlinear relationship rather than Kissinger’s linear fittings. It is suggested that the continuous heating crystallization diagrams obtained from VFT equation should be more adequate to estimate the long-term thermal stability of Nd60Al20Co20 bulk metallic glass according to the time-temperature-transformation diagram based on isothermal annealing.
Show PACS
64.70.P- Glass transitions of specific systems
64.70.Q- Theory and modeling of the glass transition
64.70.K- Solid-solid transitions
61.43.Fs Glasses
81.40.Gh Other heat and thermomechanical treatments

Relation between photoluminescence emission and local order-disorder in the CaTiO3 lattice modifier

Sergio de Lazaro, Juliana Milanez, Alberthmeiry T. de Figueiredo, Valéria M. Longo, Valmor R. Mastelaro, Fabio S. De Vicente, Antônio C. Hernandes, José A. Varela, and Elson Longo

Appl. Phys. Lett. 90, 111904 (2007); http://dx.doi.org/10.1063/1.2713359 (3 pages) | Cited 27 times

Online Publication Date: 12 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this letter, the authors propose that photoluminescence emission in CaTiO3 is affected not only by disorder in the lattice former but also by structural disorder in the lattice modifier. Structural disorder was evaluated by Ti, Ca K-edge x-ray absorption near-edge structure experiments and by photoluminescence emission. The preedge feature of the Ca K edge was related to the intensity of photoluminescence emission. The results of the preedge feature of the Ca K-edge x-ray absorption near-edge structure confirm the presence of different Ca coordination numbers, namely, Ca–O11 and Ca–O12.
Show PACS
78.55.Hx Other solid inorganic materials
78.70.Dm X-ray absorption spectra

Enhanced photosensitivity in silicate optical fibers by thermal treatment

Gilberto Brambilla and Valerio Pruneri

Appl. Phys. Lett. 90, 111905 (2007); http://dx.doi.org/10.1063/1.2714096 (3 pages) | Cited 1 time

Online Publication Date: 12 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Enhanced photosensitivity using thermal treatment has been observed on several silicate optical fibers. The effect of the treatment on fibers with different dopants has been tested via Bragg grating inscription. The presence of Ge or Sn atom has been established to be fundamental for the effect to occur. To explain the main features a model involving defect dynamics is proposed.
Show PACS
42.79.Dj Gratings
42.81.-i Fiber optics
81.40.Gh Other heat and thermomechanical treatments

Study of copper diffusion through a ruthenium thin film by photoemission electron microscopy

Wei Wei, S. L. Parker, Y.-M. Sun, J. M. White, Gang Xiong, Alan G. Joly, Kenneth M. Beck, and Wayne P. Hess

Appl. Phys. Lett. 90, 111906 (2007); http://dx.doi.org/10.1063/1.2712832 (3 pages) | Cited 6 times

Online Publication Date: 13 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Photoemission electron microscopy is used to study copper diffusion through a ruthenium thin film. The photoemission electron microscopy images display a large contrast between Cu and Ru due to the differences in work function, making photoemission electron microscopy an ideal methodology to study thin film diffusion in real time. Between 175 and 290 °C, Cu mainly diffuses through defect sites in the thin Ru film. Uniform diffusion of Cu through the Ru film begins at approximately 300 °C. The results are confirmed by x-ray photoemission spectroscopy depth profiling and scanning electron microscopy–energy dispersive x-ray spectroscopy analysis.
Show PACS
68.35.Fx Diffusion; interface formation
66.30.Ny Chemical interdiffusion; diffusion barriers
79.60.Jv Interfaces; heterostructures; nanostructures
73.30.+y Surface double layers, Schottky barriers, and work functions

Simultaneous filling of InAs quantum dot states from the GaAs barrier under nonresonant excitation

G. Rainò, G. Visimberga, A. Salhi, M. De Vittorio, A. Passaseo, R. Cingolani, and M. De Giorgi

Appl. Phys. Lett. 90, 111907 (2007); http://dx.doi.org/10.1063/1.2713347 (3 pages) | Cited 11 times

Online Publication Date: 13 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors have performed time resolved photoluminescence measurements by upconversion technique on InAs quantum dots embedded in an InGaAs/GaAs quantum well emitting at 1.3 μm at room temperature. A detailed analysis of the photoluminescence transients as a function of the excitation density and for different detection energies between the quantum dot transitions and the GaAs absorption edge shows that the intradot relaxation is slower than the direct carrier capture from the barrier states through a continuum background relaxation.
Show PACS
73.21.La Quantum dots
78.67.Hc Quantum dots
78.55.Cr III-V semiconductors
78.47.-p Spectroscopy of solid state dynamics

Propagation of Lamb waves in one-dimensional quasiperiodic composite thin plates: A split of phonon band gap

Jian Gao, Jian-Chun Cheng, and Baowen Li

Appl. Phys. Lett. 90, 111908 (2007); http://dx.doi.org/10.1063/1.2713339 (3 pages) | Cited 15 times

Online Publication Date: 13 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors study numerically the propagation of Lamb waves in one-dimensional quasiperiodic composite thin plates made of tungsten (B) and silicon resin (A) arranged according to a Fibonacci sequence. It is found that the band-gap structures of Lamb waves are very different from those of bulk waves. The split of band gaps is independent of the number of layers, which is different from the quasiperiodic bulk photonic and phononic crystals. Possible applications are discussed.
Show PACS
68.35.Iv Acoustical properties
43.35.Pt Surface waves in solids and liquids
63.20.-e Phonons in crystal lattices

Determination of Young’s modulus of individual electrospun nanofibers by microcantilever vibration method

Philip A. Yuya, Yongkui Wen, Joseph A. Turner, Yuris A. Dzenis, and Zheng Li

Appl. Phys. Lett. 90, 111909 (2007); http://dx.doi.org/10.1063/1.2713128 (3 pages) | Cited 11 times

Online Publication Date: 14 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors report a technique for measuring Young’s modulus of a single electrospun nanofiber using the vibrations of two microcantilevers coupled with the nanofiber. The modulus is calculated from the resonant frequency shift resulting from the nanofiber. Polyacrylonitrile nanofibers (200 nm diameter) were collected during electrospinning and wrapped on two similar microcantilevers causing a shift in first resonance from 10.0 to 19.4 kHz. Finite element analysis was used to analyze the frequency shift using images from a scanning electron microscope giving a modulus of the as-spun polyacrylonitrile nanofiber of 26.8 GPa.
Show PACS
07.10.Cm Micromechanical devices and systems
81.70.Bt Mechanical testing, impact tests, static and dynamic loads
81.40.Jj Elasticity and anelasticity, stress-strain relations
62.20.D- Elasticity
62.25.-g Mechanical properties of nanoscale systems

Channel cracks in a hermetic coating consisting of organic and inorganic layers

Nicolas Cordero, Juil Yoon, and Zhigang Suo

Appl. Phys. Lett. 90, 111910 (2007); http://dx.doi.org/10.1063/1.2713134 (3 pages) | Cited 11 times

Online Publication Date: 14 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Flexible electronic devices often require hermetic coatings that can withstand applied strains. This letter calculates the critical strains for various configurations of channel cracks in a coating consisting of organic and inorganic layers. The authors show that the coating can sustain the largest strain when the organic layer is of some intermediate thicknesses.
Show PACS
68.60.Bs Mechanical and acoustical properties
81.40.Np Fatigue, corrosion fatigue, embrittlement, cracking, fracture, and failure
62.20.M- Structural failure of materials

Size-dependent planar colloidal crystals guided by alternating electric field

Ke-Qin Zhang and Xiang Y. Liu

Appl. Phys. Lett. 90, 111911 (2007); http://dx.doi.org/10.1063/1.2713235 (3 pages) | Cited 7 times

Online Publication Date: 14 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors demonstrate that two-dimensional crystals can be assembled from suspensions of colloidal spheres subjected to an alternating electric field on the surface of electrodes. The order parameters of monolayer colloidal crystals, which are extracted from the translational correlation function g(r) and bond-orientational correlation function g6(r), are employed to quantitatively characterize the ordering of the colloidal assemblies. This method has been applied on colloidal spheres of various sizes ranging from 450 nm to 5.0 μm. In particular, high-quality crystals of spheres sized differently are controlled by different domains of frequency. This technique could be a rational method to assemble micro- or submicron colloidal spheres.
Show PACS
82.70.Dd Colloids
61.46.Hk Nanocrystals
81.07.Bc Nanocrystalline materials
81.16.Dn Self-assembly

Effects of rapid thermal annealing on the emission properties of highly uniform self-assembled InAs/GaAs quantum dots emitting at 1.3 μm

Tao Yang, Jun Tatebayashi, Kanna Aoki, Masao Nishioka, and Yasuhiko Arakawa

Appl. Phys. Lett. 90, 111912 (2007); http://dx.doi.org/10.1063/1.2713135 (3 pages) | Cited 14 times

Online Publication Date: 16 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors report the effects of rapid thermal annealing (RTA) on the emission properties of highly uniform self-assembled InAs quantum dots (QDs) emitting at 1.3 μm grown on GaAs substrate by metal organic chemical vapor deposition. Postgrowth RTA experiments were performed under N2 flow at temperatures ranging from 600 to 900 °C for 30 s using GaAs proximity capping. Surprisingly, in spite of the capping, large blueshifts in the emission peak (up to about 380 meV at 850 °C) were observed (even at low annealing temperatures) along with enhanced integrated photoluminescence (PL) intensities. Moreover, pronounced peak broadenings occurred at low annealing temperatures (<700 °C), indicating that RTA does not always cause peak narrowing, as is typically observed with traditional QDs with large inhomogeneous PL linewidths. The mechanism behind the large peak blueshift was studied and found to be attributed to the as-grown QDs with large size, which cause a larger dot-barrier interface and greater strain in and near the QD regions, thereby greatly promoting Ga–In intermixing across the interface during RTA. The results reported here demonstrate that it is possible to significantly shift the emission peak of the QDs by RTA without any additional procedures, even at lower annealing temperatures.
Show PACS
78.67.Hc Quantum dots
78.55.Cr III-V semiconductors
61.72.Cc Kinetics of defect formation and annealing

Multistable alignment states in nematic liquid crystal filled wells

C. Tsakonas, A. J. Davidson, C. V. Brown, and N. J. Mottram

Appl. Phys. Lett. 90, 111913 (2007); http://dx.doi.org/10.1063/1.2713140 (3 pages) | Cited 14 times

Online Publication Date: 16 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Two distinct, stable alignment states have been observed for a nematic liquid crystal confined in a layer with thickness of 12 μm and in square wells with sides of length between 20 and 80 μm. The director lies in the plane of the layer and line defects occur in two corners of the squares. The positions of the defects determine whether the director orientation is across the diagonal or is parallel to two opposite edges of the square. The device is multistable because both the diagonal and parallel states are stable when rotated by multiples of 90° in plane.
Show PACS
42.79.Kr Display devices, liquid-crystal devices

Strain field in silicon on insulator lines using high resolution x-ray diffraction

M. Gailhanou, A. Loubens, J.-S. Micha, B. Charlet, A. A. Minkevich, R. Fortunier, and O. Thomas

Appl. Phys. Lett. 90, 111914 (2007); http://dx.doi.org/10.1063/1.2713335 (3 pages) | Cited 16 times

Online Publication Date: 16 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Symmetric and asymmetric reciprocal space maps (RSMs) of silicon on insulator (SOI) lines are obtained using high resolution x-ray diffraction. RSMs calculated from the displacement field simulated using finite element calculations show a good agreement with the experimental RSMs. These calculations indicate the large influence of the displacement field created by the silicon nitride cap and the sensitivity of the RSMs to the gradients of displacement at the edge of the SOI lines. They further show that the RSMs are influenced by local strains but also by local rotations of the crystal lattice connected with the strain distribution.
Show PACS
68.60.Bs Mechanical and acoustical properties

Criterion for predicting the glass-forming ability of alloys

S. Sharma, R. Vaidyanathan, and C. Suryanarayana

Appl. Phys. Lett. 90, 111915 (2007); http://dx.doi.org/10.1063/1.2713867 (3 pages) | Cited 9 times

Online Publication Date: 16 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Mechanical alloying (MA) of blended elemental powder mixtures of Fe42Zr10X28B20 (X = Al, Co, Ge, Mn, Ni, and Sn) was carried out to determine their glass-forming ability (GFA) (as determined by the time required to form the amorphous phase). During milling, amorphization was achieved in systems with X = Al, Ge, or Ni, but not in the other systems. The GFA could be correlated with the total number of intermetallics present in the constituent binary phase diagrams. Thus, this work offers the equilibrium phase diagram as a predictive tool to determine if amorphization can be achieved by the MA method.
Show PACS
61.43.Dq Amorphous semiconductors, metals, and alloys
61.43.Fs Glasses
81.30.Bx Phase diagrams of metals, alloys, and oxides
64.70.P- Glass transitions of specific systems
64.70.Q- Theory and modeling of the glass transition
back to top
RSS Feeds

Current transport characteristics across shallow hybrid-orientation silicon bonded interfaces

M. C. Wagener, R. H. Zhang, G. A. Rozgonyi, M. Seacrist, and M. Ries

Appl. Phys. Lett. 90, 112101 (2007); http://dx.doi.org/10.1063/1.2712802 (3 pages) | Cited 9 times

Online Publication Date: 12 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This letter describes the current transport across the interface of hybrid-orientation direct silicon bonded wafers. It is observed that the position of the bonding interface relative to the wafer surface directly impacts the transport behavior. Varistor behavior occurs in the case of an interface several microns below the surface, while rectifying behavior occurs when the bonding interface is sufficiently close to the surface (200 nm) for the interface potential to fully deplete the region above the bonding interface. This phenomenon is expected to be applicable to all near-surface interfaces that have a defect-state density sufficient to pin the Fermi level within the band gap.
Show PACS
85.40.-e Microelectronics: LSI, VLSI, ULSI; integrated circuit fabrication technology
84.32.Ff Conductors, resistors (including thermistors, varistors, and photoresistors)
85.30.-z Semiconductor devices

Spin-polarized transport in ferromagnetic multilayered semiconductor nanostructures

E. J. R. Oliveira, A. T. da Cunha Lima, M. A. Boselli, G. M. Sipahi, S. C. P. Rodrigues, and I. C. da Cunha Lima

Appl. Phys. Lett. 90, 112102 (2007); http://dx.doi.org/10.1063/1.2712809 (3 pages) | Cited 2 times

Online Publication Date: 12 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The occurrence of inhomogeneous spin-density distribution in multilayered ferromagnetic diluted magnetic semiconductor nanostructures leads to strong dependence of the spin-polarized transport properties on these systems. The spin-dependent mobility, conductivity, and resistivity in (Ga,Mn)As/GaAs, (Ga,Mn)N/GaN, and (Si,Mn)/Si multilayers are calculated as a function of temperature, scaled by the average magnetization of the diluted magnetic semiconductor layers. An increase of the resistivity near the transition temperature is obtained. The authors observed that the spin-polarized transport properties change strongly among the three materials.
Show PACS
73.63.Rt Nanoscale contacts
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
73.40.Lq Other semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
72.25.Mk Spin transport through interfaces
72.25.Dc Spin polarized transport in semiconductors
75.75.-c Magnetic properties of nanostructures
75.50.Dd Nonmetallic ferromagnetic materials

Spin-orbit interaction enhanced polaron effect in two-dimensional semiconductors

Zhou Li, Zhongshui Ma, A. R. Wright, and Chao Zhang

Appl. Phys. Lett. 90, 112103 (2007); http://dx.doi.org/10.1063/1.2713346 (3 pages) | Cited 7 times

Online Publication Date: 13 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
It is shown that in two-dimensional semiconductors, the electron-phonon interaction and polaron mass correction are both significantly enhanced by the Rashba spin-orbit coupling. The mass correction is positive for the upper Rashba branch and negative for the lower Rashba branch. Both Rashba branches have the same polaron binding energy, which is higher than that for systems in the absence of spin-orbit interaction. To the leading order, the correction to the binding energy is proportional to the square of the spin-orbit coupling strength.
Show PACS
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
71.70.Ej Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect
71.38.-k Polarons and electron-phonon interactions
63.20.K- Phonon interactions
63.22.-m Phonons or vibrational states in low-dimensional structures and nanoscale materials
71.15.Nc Total energy and cohesive energy calculations

Electrical properties of oxide heteroepitaxial p-n junctions: La1−xSrxFeO3/SrTi0.99Nb0.01O3

A. Yamamoto, A. Sawa, H. Akoh, M. Kawasaki, and Y. Tokura

Appl. Phys. Lett. 90, 112104 (2007); http://dx.doi.org/10.1063/1.2712803 (3 pages) | Cited 11 times

Online Publication Date: 13 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Electrical properties of heteroepitaxial p-n junctions composed of correlated electron semiconductors La1−xSrxFeO3 (LSFO) (x = 0.4, 0.5, 0.67, and 0.8) and a band semiconductor SrTi0.99Nb0.01O3 were analyzed. The junctions exhibited rectifying current-voltage (I-V) characteristics. The built-in potential (VbiSTO) evaluated from the capacitance-voltage characteristics under reverse bias increased from 0.9 eV for x = 0.4 to 1.2 eV for x = 0.8 junctions, indicating a large downward shift in chemical potential of p-type LSFO due to hole doping. Some of the junctions showed hysteretic I-V characteristics, which have been commonly observed in resistance switching devices, but others did not. LSFO junctions with higher doping (x = 0.8) showed higher probability of hysteretic behavior.
Show PACS
73.40.Lq Other semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
73.40.Ei Rectification
65.80.-g Thermal properties of small particles, nanocrystals, nanotubes, and other related systems

On the nature of the carriers in ferromagnetic FeSe

X. J. Wu, D. Z. Shen, Z. Z. Zhang, J. Y. Zhang, K. W. Liu, B. H. Li, Y. M. Lu, B. Yao, D. X. Zhao, B. S. Li, C. X. Shan, X. W. Fan, H. J. Liu, and C. L. Yang

Appl. Phys. Lett. 90, 112105 (2007); http://dx.doi.org/10.1063/1.2712497 (3 pages) | Cited 16 times

Online Publication Date: 14 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The optical and electrical properties of FeSe thin films are studied by both optical absorption and Hall measurements, which suggest that ferromagnetic FeSe is a metal instead of a semiconductor. No absorption gap is observed in the whole spectrum range from far infrared to ultraviolet. Temperature dependent transport measurement indicates that FeSe has a resistivity about 10−3 Ω cm. It is also found that there is a transition from n-type conductivity at low temperatures to p-type conductivity at higher temperatures in FeSe, which is attributed to the two-carrier transport nature and the thermal activation of localized carriers in the thin film.
Show PACS
78.66.Bz Metals and metallic alloys
73.61.At Metal and metallic alloys
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
72.60.+g Mixed conductivity and conductivity transitions
72.15.Gd Galvanomagnetic and other magnetotransport effects
72.15.Rn Localization effects (Anderson or weak localization)

Assembly of one-dimensional nanorods into Bi2S3 films with enhanced thermoelectric transport properties

Sheng-Cong Liufu, Li-Dong Chen, Qin Yao, and Chun-Fen Wang

Appl. Phys. Lett. 90, 112106 (2007); http://dx.doi.org/10.1063/1.2712504 (3 pages) | Cited 33 times

Online Publication Date: 14 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Bismuth sulfide thin films have been assembled by cross-linkage nanorods on surface-functionalized Si substrate with self-assembled monolayers. Results of transmission electron microscopy and electron diffraction revealed that highly crystalline Bi2S3 nanorods grow along c-axis direction. Electrical transport properties including resistivity (0.02 Ω cm), thermopower (−755 μV K−1), and carrier mobilities (1100 cm2 V−1 s−1) of the Bi2S3 films at 300 K are found superior to those of previously reported Bi2S3 samples. The Bi2S3 films exhibit a maximum thermoelectric power factor (3.97×10−3 W m−1 K−2) at 450 K. The enhancement of thermoelectric properties mainly originates from highly crystalline and oriented nanostructures embedded in the Bi2S3 films.
Show PACS
81.16.Dn Self-assembly
61.46.-w Structure of nanoscale materials
81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
73.63.Bd Nanocrystalline materials
73.50.Lw Thermoelectric effects
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)

Doping dependence of thermopower and thermoelectricity in strongly correlated materials

Subroto Mukerjee and Joel E. Moore

Appl. Phys. Lett. 90, 112107 (2007); http://dx.doi.org/10.1063/1.2712775 (3 pages) | Cited 12 times

Online Publication Date: 14 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The search for efficient semiconductor thermoelectrics has been greatly aided by theoretical modeling of electron and phonon transports in bulk materials and nanocomposites. Recent experiments have studied thermoelectric transport in thermoelectrics that are “strongly correlated” and derived by doping Mott insulators. Here a unified theory of electrical and thermal transport in the atomic and “Heikes” limit is applied to understand recent experiments on sodium cobaltate and other doped Mott insulators at room temperature and above. For optimal electron filling, a broad class of narrow-bandwidth correlated materials is shown to have thermoelectric power factors as high as in the best semiconductors.
Show PACS
72.20.Pa Thermoelectric and thermomagnetic effects
71.27.+a Strongly correlated electron systems; heavy fermions
61.72.up Other materials
71.10.Fd Lattice fermion models (Hubbard model, etc.)

Formation of stacked Ni silicide nanocrystals for nonvolatile memory application

Wei-Ren Chen, Ting-Chang Chang, Po-Tsun Liu, Po-Sun Lin, Chun-Hao Tu, and Chun-Yen Chang

Appl. Phys. Lett. 90, 112108 (2007); http://dx.doi.org/10.1063/1.2713177 (3 pages) | Cited 24 times

Online Publication Date: 14 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The formation of stacked Ni silicide nanocrystals by using a comixed target is proposed in this letter. High resolution transmission electron microscope analysis clearly shows the stacked nanocrystals embedded in the silicon oxide. The memory window enough to define “1” and “0” states is obviously observed at low voltage programming conditions, and good data retention characteristics are exhibited for the nonvolatile memory application. A physical model is also proposed further to explain the saturation phenomenon of threshold voltage at different programming voltages with operation duration.
Show PACS
81.07.Bc Nanocrystalline materials
61.46.Hk Nanocrystals
68.37.Lp Transmission electron microscopy (TEM)
84.30.Sk Pulse and digital circuits

Photoluminescence from low temperature grown InAs/GaAs quantum dots

D. Sreenivasan, J. E. M. Haverkort, T. J. Eijkemans, and R. Nötzel

Appl. Phys. Lett. 90, 112109 (2007); http://dx.doi.org/10.1063/1.2713803 (3 pages) | Cited 7 times

Online Publication Date: 14 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors investigated a set of self-assembled InAs/GaAs quantum dots (QDs) formed by molecular beam epitaxy at low temperature (LT, 250 °C) and postgrowth annealing. A QD photoluminescence (PL) peak around 1.01 eV was observed. The PL efficiency quickly quenches between 6 and 40 K due to the tunneling out of the QD into traps within the GaAs barrier. The PL efficiency increases by a factor of 45–280 when exciting below the GaAs band gap, directly into the InAs QD layer. This points towards good optical quality QDs, which are embedded in a LT-GaAs barrier with a high trapping efficiency.
Show PACS
78.67.Hc Quantum dots
78.55.Cr III-V semiconductors
61.72.Cc Kinetics of defect formation and annealing
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
73.40.Gk Tunneling

Alpha-particle irradiation-induced defects in n-type germanium

Vl. Kolkovsky, M. Christian Petersen, and A. Nylandsted Larsen

Appl. Phys. Lett. 90, 112110 (2007); http://dx.doi.org/10.1063/1.2713864 (3 pages) | Cited 3 times

Online Publication Date: 14 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Deep level transient spectroscopy and high-resolution Laplace deep level transient spectroscopy were used to investigate alpha-particle irradiation-induced defects in n-type Ge. It is proposed that there is no electrically active divacancy level in the upper half of the band gap. A dominant peak has been observed at alpha-particle doses higher than about 6×1010 cm−2. The electronic and annealing properties of the defect have been investigated. The defect is suggested to be a multivacancy complex.
Show PACS
71.55.Cn Elemental semiconductors
61.80.Jh Ion radiation effects
61.82.Fk Semiconductors
61.72.Cc Kinetics of defect formation and annealing
61.72.J- Point defects and defect clusters

Electron density dependence of in-plane spin relaxation anisotropy in GaAs/AlGaAs two-dimensional electron gas

Baoli Liu, Hongming Zhao, Jia Wang, Linsheng Liu, Wenxin Wang, Dongmin Chen, and Haijun Zhu

Appl. Phys. Lett. 90, 112111 (2007); http://dx.doi.org/10.1063/1.2713353 (3 pages) | Cited 16 times

Online Publication Date: 15 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors investigated the spin dynamics of two-dimensional electrons in (001) GaAs/AlGaAs heterostructure using the time-resolved Kerr rotation technique under a transverse magnetic field. The in-plane spin lifetime is found to be anisotropic below 150 K due to the interference of Rashba [J. Phys. C 17, 6039 (1984)] and Dresselhaus [Phys. Rev. 100, 580 (1955)] spin-orbit coupling and D’yakonov-Perel [Sov. Phys. Solid State 13, 3023 (1972)] spin relaxation. The ratio of in-plane spin lifetimes is measured directly as a function of temperature and pump power, showing that the electron density in two-dimensional electron gas channel strongly affects the Rashba spin-orbit coupling.
Show PACS
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
71.70.Ej Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect

Effects of (NH4)2Sx treatment on electrical properties of indium tin oxide/poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate)

Yow-Jon Lin, Hsing-Cheng Chang, and Bei-Yuan Liu

Appl. Phys. Lett. 90, 112112 (2007); http://dx.doi.org/10.1063/1.2714290 (3 pages) | Cited 3 times

Online Publication Date: 16 March 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The effects of (NH4)2Sx treatment on the current-voltage characteristics and interfacial properties of the indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT-PSS) samples have been investigated in this study. The authors found that (NH4)2Sx treatment could lead to the improvement of the interfacial stability of ITO/PEDOT-PSS samples. In addition, the current transport at the ITO/PEDOT-PSS interface is governed by the defects induced by interfacial reactions.
Show PACS
73.40.-c Electronic transport in interface structures
68.35.Ct Interface structure and roughness
Page 2 of 5 Pages Previous Page Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close