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

10 Sep 2001

Volume 79, Issue 11, pp. 1587-1734

Page 1 of 3 Pages Next Page | Jump to Page
back to top
RSS Feeds

Formation of radially and azimuthally polarized light using space-variant subwavelength metal stripe gratings

Ze’ev Bomzon, Vladimir Kleiner, and Erez Hasman

Appl. Phys. Lett. 79, 1587 (2001); http://dx.doi.org/10.1063/1.1401091 (3 pages) | Cited 42 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present a unique method for converting circularly polarized light into radially and azimuthally polarized beams. The method is based on the use of computer-generated space-variant subwavelength metal stripe gratings. The elements were realized on GaAs substrates and produced beams with high polarization purity at a wavelength of 10.6 μm. As a result of the conversion, the beams also undergo space-variant phase modification, which has an effect on their propagation. We demonstrate the effect experimentally, and calculate it using full space-variant polarization and phase analysis based on rigorous coupled-wave analysis and Jones calculus. © 2001 American Institute of Physics.
Show PACS
42.79.Ci Filters, zone plates, and polarizers
42.40.Eq Holographic optical elements; holographic gratings
42.40.Jv Computer-generated holograms
42.79.Dj Gratings
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation

Intersubband absorption in degenerately doped GaN/AlxGa1−xN coupled double quantum wells

Claire Gmachl, Hock M. Ng, and Alfred Y. Cho

Appl. Phys. Lett. 79, 1590 (2001); http://dx.doi.org/10.1063/1.1403277 (3 pages) | Cited 75 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Intersubband absorption in coupled GaN/AlGaN double quantum wells (DQWs) has been measured. The samples were grown by molecular-beam epitaxy on a sapphire substrate and with large (0.65 or 0.9) AlN-mole fraction in the barriers. Peak absorption wavelengths as short as 1.35 and 1.52 μm were measured for a symmetric DQW of 12 Å wide wells coupled by a 10 Å wide barrier, which also showed evidence of excited-state anticrossing. As expected, asymmetric DQWs displayed no such anticrossing, and the ground-state anticrossing energies were found to be much smaller, as a result of the comparatively large effective electron mass, than the energy broadening of individual transitions. Degenerate doping of the DQWs was used to establish a common reference energy at the Fermi level, which allows overcoming uncertainties related to intrinsic internal electric fields. The asymmetric DQWs displayed peak absorption wavelengths between 1.5 and 2.9 μm. © 2001 American Institute of Physics.
Show PACS
71.55.Eq III-V semiconductors
78.66.Fd III-V semiconductors
73.21.Fg Quantum wells
78.67.De Quantum wells
61.72.uj III-V and II-VI semiconductors

Evanescent and propagating wave characteristics of the photonic quantum ring laser

B. H. Park, J. C. Ahn, J. Bae, J. Y. Kim, M. S. Kim, S. D. Baek, and O’Dae Kwon

Appl. Phys. Lett. 79, 1593 (2001); http://dx.doi.org/10.1063/1.1402655 (3 pages) | Cited 13 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present the wave propagation characteristics of photonic quantum ring lasers with clear evidence of the evanescence-propagation crossover behavior. The data obtained from the fiber probe measurements of 15–36 μm disk size lasers show that the Rayleigh’s whispering gallery modes always give rise to the propagation mode, with the crossover ranges of 55–80 μm. The three-dimensional but chiral and broken z-axis symmetry nature of the photonic quantum ring cavity appears to guarantee such a crossover to the propagation in general. © 2001 American Institute of Physics.
Show PACS
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.50.Gy Effects of atomic coherence on propagation, absorption, and amplification of light; electromagnetically induced transparency and absorption
42.55.Px Semiconductor lasers; laser diodes
42.55.Sa Microcavity and microdisk lasers
back to top
RSS Feeds

Electron temperature analysis of two-gas-species inductively coupled plasma

K. H. Bai, H. Y. Chang, and H. S. Uhm

Appl. Phys. Lett. 79, 1596 (2001); http://dx.doi.org/10.1063/1.1404135 (3 pages) | Cited 15 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The electron energy distribution functions and electron temperatures are measured in Ar/He and Ar/Xe inductively coupled plasma with various mixing ratios. The electron temperature does not change linearly with the mixing ratios; instead it increases abruptly near PHe/PAr+He = 1 and decreases rapidly near PXe/PAr+Xe = 0. A simple model using a two-ion-species fluid model is suggested to explain the electron temperature variations, and it agrees well with the experimental results. © 2001 American Institute of Physics.
Show PACS
52.27.Cm Multicomponent and negative-ion plasmas
52.70.Ds Electric and magnetic measurements
52.25.-b Plasma properties
back to top
RSS Feeds

Stimulated-emission phenomena from InGaN/GaN multiple-quantum wells grown by plasma-assisted molecular-beam epitaxy

X. Q. Shen, M. Shimizu, H. Okumura, and F. Sasaki

Appl. Phys. Lett. 79, 1599 (2001); http://dx.doi.org/10.1063/1.1402650 (3 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Time-resolved photoluminescence measurements at 5 K were performed to study the optical properties of InGaN/GaN multiple-quantum wells (MQWs) grown by plasma-assisted molecular-beam epitaxy (rf-MBE). Stimulated-emission (SE) phenomena by optical pumping were observed under the high-excitation density from the InGaN/GaN MQW samples with the In composition varying from 0.04 to 0.16. It was found that the threshold density for SE phenomena strongly depended on the In composition, where the lowest threshold density was 69 μJ/cm2 from our samples. Our results show a potential of rf-MBE technique for the future optical device applications. © 2001 American Institute of Physics.
Show PACS
78.55.Cr III-V semiconductors
78.47.-p Spectroscopy of solid state dynamics
78.45.+h Stimulated emission
78.67.De Quantum wells

Thermal expansion and elastic properties of InN

Kai Wang and Robert R. Reeber

Appl. Phys. Lett. 79, 1602 (2001); http://dx.doi.org/10.1063/1.1400082 (3 pages) | Cited 24 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The thermal expansion coefficients of wurtzite structure InN are evaluated within the constraints of a basic model and predicted for an extended temperature range. Together with the elastic constants provided earlier, this information gives a basis for optimizing thin-film growth conditions and thereby reducing the residual stresses in group-III-nitride thin-film devices. © 2001 American Institute of Physics.
Show PACS
68.60.Bs Mechanical and acoustical properties
68.60.Wm Other nonelectronic physical properties
65.40.De Thermal expansion; thermomechanical effects
62.20.D- Elasticity
68.55.A- Nucleation and growth

Vitrification and determination of the crystallization time scales of the bulk-metallic-glass-forming liquid Zr58.5Nb2.8Cu15.6Ni12.8Al10.3

C. C. Hays, J. Schroers, W. L. Johnson, T. J. Rathz, R. W. Hyers, J. R. Rogers, and M. B. Robinson

Appl. Phys. Lett. 79, 1605 (2001); http://dx.doi.org/10.1063/1.1398605 (3 pages) | Cited 24 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The crystallization kinetics of Zr58.5Nb2.8Cu15.6Ni12.8Al10.3 were studied in an electrostatic levitation (ESL) apparatus. The measured critical cooling rate is 1.75 K/s. Zr58.5Nb2.8Cu15.6Ni12.8Al10.3 is the first bulk-metallic-glass-forming liquid that does not contain beryllium to be vitrified by purely radiative cooling in the ESL. Furthermore, the sluggish crystallization kinetics enable the determination of the time-temperature-transformation (TTT) diagram between the liquidus and the glass transition temperatures. The shortest time to reach crystallization in an isothermal experiment; i.e., the nose of the TTT diagram is 32 s. The nose of the TTT diagram is at 900 K and positioned about 200 K below the liquidus temperature. © 2001 American Institute of Physics.
Show PACS
81.05.Kf Glasses (including metallic glasses)
64.70.D- Solid-liquid transitions
64.70.P- Glass transitions of specific systems
64.70.Q- Theory and modeling of the glass transition
81.30.Bx Phase diagrams of metals, alloys, and oxides
61.43.Fs Glasses

Atomically accurate Si grating with 5.73 nm period

A. Kirakosian, R. Bennewitz, J. N. Crain, Th. Fauster, J.-L. Lin, D. Y. Petrovykh, and F. J. Himpsel

Appl. Phys. Lett. 79, 1608 (2001); http://dx.doi.org/10.1063/1.1401788 (3 pages) | Cited 69 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A vicinal surface of silicon is found that exhibits an atomically accurate step pattern with a period of 5.73 nm, corresponding to 17 atomic rows per (111) terrace. It can be viewed as reconstructed Si(557) surface, where a triple step is combined with a single Si(111)7×7 unit. The driving forces for establishing regular step patterns are discussed. © 2001 American Institute of Physics.
Show PACS
68.35.B- Structure of clean surfaces (and surface reconstruction)
68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)
81.05.Cy Elemental semiconductors
81.07.-b Nanoscale materials and structures: fabrication and characterization
81.16.-c Methods of micro- and nanofabrication and processing

Evidence for strain-induced lateral carrier confinement in InGaAs quantum wells by low-temperature near-field spectroscopy

U. Zeimer, F. Bugge, S. Gramlich, V. Smirnitski, M. Weyers, G. Tränkle, J. Grenzer, U. Pietsch, G. Cassabois, V. Emiliani, and Ch. Lienau

Appl. Phys. Lett. 79, 1611 (2001); http://dx.doi.org/10.1063/1.1402638 (3 pages) | Cited 4 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A strain-induced lateral variation of the band edges of a 10-nm-thick In0.16Ga0.84As quantum well embedded in GaAs is achieved by patterning of a 100-nm-thick compressively strained In0.52Ga0.48P stressor layer. The strain modulation results in a splitting of the 10 K far-field photoluminescence (PL) spectra into two emission peaks. Spectrally resolved two-dimensional near-field PL images establish a clear spatial and spectral separation of the two far-field PL peaks, indicating a lateral carrier confinement with a confinement energy of about 10 meV. Finite-element calculations of the strain distribution are used to determine the lateral band-edge shifts and are well in agreement with the experimental findings. © 2001 American Institute of Physics.
Show PACS
78.67.De Quantum wells
78.55.Cr III-V semiconductors
78.66.Fd III-V semiconductors
81.05.Ea III-V semiconductors
68.65.Fg Quantum wells
73.21.Fg Quantum wells

Incorporation kinetics of indium in indium gallium nitride at low temperature

D. F. Storm, C. Adelmann, and B. Daudin

Appl. Phys. Lett. 79, 1614 (2001); http://dx.doi.org/10.1063/1.1400081 (2 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Recently, a phenomenological model of the incorporation kinetics of indium in indium gallium nitride was proposed based on published data from InGaN growth at relatively high fluxes and high substrate temperature, TS = 650 °C. We present data from growths at much lower fluxes and at a significantly lower substrate temperature, which are also very well described by this model, as well as data for which the model appears less satisfactory. The nature of the indium self-blocking mechanism and the dependence of the model’s fitting parameters on the substrate temperature are discussed. © 2001 American Institute of Physics.
Show PACS
81.05.Ea III-V semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.Nq Composition and phase identification

Self-assembled AlInGaN quaternary superlattice structures

N. A. El-Masry, M. K. Behbehani, S. F. LeBoeuf, M. E. Aumer, J. C. Roberts, and S. M. Bedair

Appl. Phys. Lett. 79, 1616 (2001); http://dx.doi.org/10.1063/1.1400763 (3 pages) | Cited 7 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
When an AlInGaN quaternary alloy is grown by metalorganic chemical-vapor deposition under certain growth conditions, a self-assembled superlattice structure is obtained. The superlattice structure is made of quaternary layers with different AIN and InN compositions. Transmission electron microscopy data show that the superlattice periodicity is regular with an individual layer thickness that depends on the growth conditions. Secondary ion mass spectrometry measurements show that the layers’ composition alternate between high-AIN and InN content and low-AlN and-InN content, while the in-plane lattice constant remains constant for both layers. A model is presented as a preliminary effort to explain these results. © 2001 American Institute of Physics.
Show PACS
73.61.Ey III-V semiconductors
68.65.Cd Superlattices
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.05.Ea III-V semiconductors
81.16.Dn Self-assembly

Reduction in crystallographic tilting of lateral epitaxial overgrown GaN by removal of oxide mask

Min Hong Kim, Yoonho Choi, Jaehyung Yi, Min Yang, Jina Jeon, Sungwon Khym, and Shi-Jong Leem

Appl. Phys. Lett. 79, 1619 (2001); http://dx.doi.org/10.1063/1.1403236 (3 pages) | Cited 8 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The lateral overgrowth of GaN was carried out by low-pressure metalorganic chemical vapor deposition. SiO2 mask was removed just before coalescence and a subsequent lateral overgrowth was carried out to complete the fabrication of a SiO2-removed lateral epitaxial overgrown (LEO) GaN layer. The crystallographic tilting of (0002) plane, that was apparent in our standard LEO GaN layers, was absent in SiO2-removed LEO layer and x-ray diffraction measurement indicated a superior crystallinity for the SiO2-removed LEO layer. These results are attributed to the elimination of the interface between oxide mask and laterally grown GaN layer. The reduced crystallographic tilting in SiO2-removed LEO GaN layer also enhanced the quality of the coalesced fronts, as determined from cathodoluminescence images. © 2001 American Institute of Physics.
Show PACS
68.55.A- Nucleation and growth
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.15.Kk Vapor phase epitaxy; growth from vapor phase
81.05.Ea III-V semiconductors
78.60.Hk Cathodoluminescence, ionoluminescence
78.66.Fd III-V semiconductors

Reduction of nonradiative recombination centers in V-grooved AlGaAs/GaAs quantum wires grown using tertiarybutylarsine

Xing-Quan Liu, Xue-Lun Wang, and Mutsuo Ogura

Appl. Phys. Lett. 79, 1622 (2001); http://dx.doi.org/10.1063/1.1403235 (3 pages) | Cited 9 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report our comparative study on the luminescence recombination processes of V-grooved AlGaAs/GaAs quantum wires (QWRs) grown using tertiarybutylarsine (TBAs) and AsH3 as arsenic sources. Constant integrated photoluminescence (PL) intensity up to 120 K, as well as radiative efficiency of about 3000 times higher at room temperature, were observed for the TBAs sample compared with the AsH3 sample. Time-resolved PL measurements show a maximum decay time at temperature of as high as 240 K for the TBAs sample, which is about 100 K higher than that of similar samples grown using AsH3 as the arsenic source. These results suggest a dramatic reduction of nonradiative centers in QWR regions grown using TBAs as the arsenic source. © 2001 American Institute of Physics.
Show PACS
78.66.Fd III-V semiconductors
78.55.Cr III-V semiconductors
78.67.Lt Quantum wires
73.21.Hb Quantum wires
71.55.Eq III-V semiconductors
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy

Quantitative in situ nanoindentation in an electron microscope

A. M. Minor, J. W. Morris, and E. A. Stach

Appl. Phys. Lett. 79, 1625 (2001); http://dx.doi.org/10.1063/1.1400768 (3 pages) | Cited 55 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the development of a method for quantitative, in situ nanoindentation in an electron microscope and its application to study the onset of deformation during the nanoindentation of aluminum films. The force–displacement curve developed shows the characteristic “staircase” instability at the onset of plastic deformation. This instability corresponds to the first appearance of dislocations in a previously defect-free grain. Plastic deformation proceeds through the formation and propagation of prismatic loops punched into the material, and half loops that emanate from the sample surface. These results represent the first real time observations of the discrete microstructural events that occur during nanoindentation. © 2001 American Institute of Physics.
Show PACS
68.35.Gy Mechanical properties; surface strains
68.60.Bs Mechanical and acoustical properties
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
62.20.F- Deformation and plasticity
81.40.Lm Deformation, plasticity, and creep
61.72.Lk Linear defects: dislocations, disclinations

Analytic solution of stress distribution under a thin film edge in substrates

S. P. Wong, H. J. Peng, and Shounan Zhao

Appl. Phys. Lett. 79, 1628 (2001); http://dx.doi.org/10.1063/1.1404130 (3 pages) | Cited 6 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have obtained an analytic solution for the stress distribution under a thin film edge in isotropic substrates of finite thickness and of infinite extent in the other two directions. Far from the film edge on the side without the film, all stress components are zero and far from the film edge under the film, the stress distribution is in accordance with that given by the bimetallic strip theory. To demonstrate the validity of this solution, the experimental infrared photoelastic stress fringe pattern obtained by a dark-field plane polariscope in a Si substrate under an oxide film edge was successfully reproduced using this solution. © 2001 American Institute of Physics.
Show PACS
68.60.Bs Mechanical and acoustical properties
62.20.D- Elasticity
78.20.hb Piezo-optical, elasto-optical, acousto-optical, and photoelastic effects
back to top
RSS Feeds

Current deep-level transient spectroscopy investigation of acceptor levels in Mg-doped GaN

Yoshitaka Nakano and Tetsu Kachi

Appl. Phys. Lett. 79, 1631 (2001); http://dx.doi.org/10.1063/1.1401779 (3 pages) | Cited 10 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The current deep-level transient spectroscopy (I-DLTS) technique was used to investigate acceptor levels in Mg-doped GaN grown by metalorganic vapor phase epitaxy. For activation of the Mg dopants, rapid thermal annealing was performed with a SiO2 encapsulation layer at 850 °C in N2. I-DLTS measurements on the Schottky diode fabricated revealed a discrete deep level located ∼112 meV above the valence band, corresponding to the energy level measured by conventional thermal admittance spectroscopy. This energy level is also in good agreement with the frequency dependence of the capacitance in view of the characteristic frequency. Therefore, this energy level can most probably be attributed to the Mg acceptor state itself. © 2001 American Institute of Physics.
Show PACS
71.55.Eq III-V semiconductors
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
61.72.Cc Kinetics of defect formation and annealing
61.82.Fk Semiconductors

High-temperature electron transport properties in AlGaN/GaN heterostructures

Narihiko Maeda, Kotaro Tsubaki, Tadashi Saitoh, and Naoki Kobayashi

Appl. Phys. Lett. 79, 1634 (2001); http://dx.doi.org/10.1063/1.1400779 (3 pages) | Cited 38 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Electron transport properties in the Al0.15Ga0.85N/GaN heterostructure field effect transistors (HFETs) have been examined from room temperature up to 400 °C. The temperature dependencies of the two-dimensional electron gas (2DEG) mobility have been systematically measured for the samples with different 2DEG densities. The 2DEG mobility has been shown to decrease with increasing the temperature, with the lower decrease ratio at higher temperatures, and moreover, shown to be less dependent on the 2DEG density at higher temperatures. These features well agree with those of the longitudinal optical phonon-limited mobility theoretically predicted, although the effect of alloy and interface scattering should further be examined and analyzed. The observed 2DEG mobilities at 400 °C were as high as from 100 to 120 cm2/V s, directly providing the evidence for suitability of the HFET of this material system for high-temperature applications. Moreover, Si-doped Al0.15Ga0.85N single layer has been shown to exhibit a relatively high bulk mobility of 50 cm2/V s at 400 °C, suggesting that AlGaN is attractive as the channel material when higher-voltage and higher-temperature device operation is required. © 2001 American Institute of Physics.
Show PACS
85.30.Tv Field effect devices
72.80.Ey III-V and II-VI semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
72.20.Fr Low-field transport and mobility; piezoresistance
71.38.-k Polarons and electron-phonon interactions

Coexistence behavior of the CuPtB-type and the CuAu–I-type ordered structures in highly strained CdxZn1−xTe/GaAs heterostructures

H. S. Lee, J. Y. Lee, T. W. Kim, D. U. Lee, D. C. Choo, and H. L. Park

Appl. Phys. Lett. 79, 1637 (2001); http://dx.doi.org/10.1063/1.1398617 (3 pages) | Cited 5 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Ordered structures in highly strained CdxZn1−xTe/GaAs heterostructures epitaxial layers grown on (001)GaAs substrates were investigated by using selected area electron diffraction pattern (SADP) and cross-sectional high-resolution transmission electron microscopy (HRTEM) measurements. The SADP results showed two sets of (1/2 1/2 1/2) superstructure reflections with symmetrical intensities along the [110] axis, and the corresponding HRTEM images indicated a doublet periodicity in the contrast of the {111} lattice planes. Two structures, one corresponding to the CuPtB-type ordering for each direction of the doublet periodicity on the {111} lattice planes along the [110] axis and the other corresponding to superstructure spots related to the CuAu–I type ordering were observed in the SADP. The doublet periodicity of 200 lattice fringes, associated with the CuAu–I-type ordered structure was also observed in the HRTEM image, and many antiphase boundaries were observed in ordered regions. The formation of the two ordered structures in the CdxZn1−xTe epilayers might originate from the minimization of the relaxation energy due to the high strain effect resulting from the large lattice mismatch between the CdxZn1−xTe epilayer and the GaAs substrate. These results provide important information on the microstructural properties for improving the efficiencies of CdxZn1−xTe-based optoelectronic devices operating in the blue-green spectral region. © 2001 American Institute of Physics.
Show PACS
68.35.Ct Interface structure and roughness
68.55.-a Thin film structure and morphology
68.37.Lp Transmission electron microscopy (TEM)

Opacity of KCl single crystal shocked above the transition pressure

Eugene Zaretsky

Appl. Phys. Lett. 79, 1640 (2001); http://dx.doi.org/10.1063/1.1398606 (3 pages) | Cited 1 time

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Strong absorption of light by shock-transformed KCl (potassium chloride) single crystal has been used for measurement of electrical conductivity of its high-pressure B2 phase. The obtained conductivity values allow the determination of the width W of the gap between the valence and the conduction bands and its dependence W = W0(1−bε) on the compressive strain ε. The values of the gap width W0 = 0.49±0.06 eV and of the parameter b = 1.4±0.4 lead to the conclusion that KCl in its high-pressure modification is a semiconductor. © 2001 American Institute of Physics.
Show PACS
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
72.20.Fr Low-field transport and mobility; piezoresistance
72.80.Jc Other crystalline inorganic semiconductors
62.50.-p High-pressure effects in solids and liquids
71.20.Nr Semiconductor compounds
64.70.K- Solid-solid transitions

Trends in bonding configuration at SiC/III–V semiconductor interfaces

Jin-Cheng Zheng, Hui-Qiong Wang, A. T. S. Wee, and C. H. A. Huan

Appl. Phys. Lett. 79, 1643 (2001); http://dx.doi.org/10.1063/1.1402162 (3 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The structural and electronic properties of interfaces between β-SiC and III–V semiconductors are studied by first-principles calculations. Favorable bonding configurations are found to form between Si–V and C–III (model A) for BN, AlN, AlP, AlAs, GaN, GaP, GaAs, InN, InP, InAs, and InSb, and Si–III and C–V (model B) for BP, BAs, BSb, AlSb, and GaSb. The relationship between the formation energy difference and lattice constant difference, as well as the charge distribution, for these two models is found. The origin of bonding configurations can be explained in terms of the ionicity of III–V semiconductors, electrostatic effect, charge distribution, and band-structure component. © 2001 American Institute of Physics.
Show PACS
68.35.Ct Interface structure and roughness
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
68.35.Np Adhesion
back to top
RSS Feeds

Thermal energy consideration in micromagnetic simulation for laminated antiferromagnetically coupled recording media

C. H. Hee, J. P. Wang, S. N. Piramanayagam, and T. C. Chong

Appl. Phys. Lett. 79, 1646 (2001); http://dx.doi.org/10.1063/1.1402658 (3 pages) | Cited 7 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Contribution of thermal energy, has been included in the micromagnetic simulation of laminated antiferromagnetically coupled (LAC) media. The antiferromagnetic coupling constant, J, required to obtain Mrt reduction in the existing simulation studies (T = 0 K) of LAC media is much higher than the experimental values. In this letter, we describe some experimental results, which point out that the contribution of thermal energy in Mrt reduction is significant. Consequently, we find that the values of J and the reversal fields are comparable to the experimental results, when thermal energy (T = 300 K) is included in the simulation. © 2001 American Institute of Physics.
Show PACS
75.50.Ss Magnetic recording materials
75.60.Jk Magnetization reversal mechanisms
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
75.30.Et Exchange and superexchange interactions
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects

Transport behavior and critical current densities in MgB2 wires

A. K. Pradhan, Y. Feng, Y. Zhao, N. Koshizuka, L. Zhou, P. X. Zhang, X. H. Liu, P. Ji, S. J. Du, and C. F. Liu

Appl. Phys. Lett. 79, 1649 (2001); http://dx.doi.org/10.1063/1.1403278 (3 pages) | Cited 12 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the transport and magnetization properties of MgB2 wires fabricated by a powder-in-tube (PIT) technique. Temperature and magnetic-field-dependent resistivity displays a high conductivity and upper critical field Hc2 generally observed in dense samples. The electronic mass anisotropy γ ≈ 1.3±0.15 predicts some texturing in the wire. Our data on transition temperature TC, Hc2, and both magnetic and transport critical current density Jc indicate that MgB2 can be manufactured in a wire form using a PIT technique and required engineering Jc can be achieved on further optimization. © 2001 American Institute of Physics.
Show PACS
74.25.Sv Critical currents
74.72.-h Cuprate superconductors
74.25.Ha Magnetic properties including vortex structures and related phenomena
74.25.F- Transport properties

Spin engineering in ultrathin Co0.35Pd0.65 alloy films

Sang-Koog Kim, Jeong-Won Lee, Jong-Ryul Jeong, Jonggeol Kim, and Sung-Chul Shin

Appl. Phys. Lett. 79, 1652 (2001); http://dx.doi.org/10.1063/1.1402153 (3 pages) | Cited 11 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The easy axis of magnetization in CoxPd1−x alloy films with x = 0.35 is controllably engineered by varying the thickness, tPd, of the Pd overlayers directly deposited on the alloy layers. In a Pd(50 Å)/CoPd (20 Å)/Pd (tPd) sample with a 10-Å-height step-wedge Pd layer, the easy axis smoothly changes from in-plane orientation (tPd = 0Å) through canted out of plane (0<tPd<30 Å) to perpendicular (30 ⩽ tPd⩽60 Å). We also demonstrate that the spin switching is controllably reversible between in-plane and perpendicular orientations when the individual constituent layers of CoPd and Pd are alternately deposited. Smoothly continuous spin reorientation in a Pd (50 Å)/CoPd (30 Å)/Pd (tPd) film with increasing tPd in a broad range of 0–150 Å convincingly evidences the magnetoelastic anisotropy origin for the observed spin switching. © 2001 American Institute of Physics.
Show PACS
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
75.40.Gb Dynamic properties (dynamic susceptibility, spin waves, spin diffusion, dynamic scaling, etc.)
75.80.+q Magnetomechanical effects, magnetostriction
75.30.Gw Magnetic anisotropy

Large magnetoresistance in Fe/MgO/FeCo(001) epitaxial tunnel junctions on GaAs(001)

M. Bowen, V. Cros, F. Petroff, A. Fert, C. Martínez Boubeta, J. L. Costa-Krämer, J. V. Anguita, A. Cebollada, F. Briones, J. M. de Teresa, L. Morellón, M. R. Ibarra, F. Güell, F. Peiró, and A. Cornet

Appl. Phys. Lett. 79, 1655 (2001); http://dx.doi.org/10.1063/1.1404125 (3 pages) | Cited 103 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present tunneling experiments on Fe(001)/MgO(20 Å)/FeCo(001) single-crystal epitaxial junctions of high quality grown by sputtering and laser ablation. Tunnel magnetoresistance measurements give 60% at 30 K, to be compared with 13% obtained recently on (001)-oriented Fe/amorphous-Al2O3/FeCo tunnel junctions. This difference demonstrates that the spin polarization of tunneling electrons is not directly related to the density of states of the free metal surface—Fe(001) in this case—but depends on the actual electronic structure of the entire electrode/barrier system. © 2001 American Institute of Physics.
Show PACS
75.47.De Giant magnetoresistance
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
73.40.Gk Tunneling
back to top
RSS Feeds

Effect of annealing atmosphere on domain structures and electromechanical properties of Pb(Zn1/3Nb2/3)O3-based ceramics

Huiqing Fan, Gun-Tae Park, Jong-Jin Choi, and Hyoun-Ee Kim

Appl. Phys. Lett. 79, 1658 (2001); http://dx.doi.org/10.1063/1.1402653 (3 pages) | Cited 18 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Annealing atmosphere effects on domain structures and electrical properties of Pb[(Zn1/3Nb2/3)0.5(Zr0.47Ti0.53)0.5]O3 (PZN–PZT) ferroelectric materials were investigated. The PZN–PZT specimens were annealed in argon, air, oxygen, and PbZrO3 atmospheres after being sintered at 1100 °C in air. The as-sintered specimens were composed of large plate-like domains. When the specimen was annealed in flowing oxygen atmosphere for 8 h at 960 °C, the domains were refined into fine twin-like domains; whereas when the specimen was annealed in argon atmosphere, the domains were modified into needle-like structures. These modifications to the domain structures have a strong effect on the electromechanical properties of this material. The formation and redistribution of lead and oxygen vacancies during thermal annealing were responsible for those variations in domain structures and electrical properties. © 2001 American Institute of Physics.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
81.05.Je Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides)
77.80.Dj Domain structure; hysteresis
81.40.Gh Other heat and thermomechanical treatments
77.65.-j Piezoelectricity and electromechanical effects
61.72.Cc Kinetics of defect formation and annealing
Page 1 of 3 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close