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

19 Oct 1998

Volume 73, Issue 16, pp. 2233-2380

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

Analysis of terahertz pulse measurement with a chirped probe beam

F. G. Sun, Zhiping Jiang, and X.-C. Zhang

Appl. Phys. Lett. 73, 2233 (1998); http://dx.doi.org/10.1063/1.121685 (3 pages) | Cited 27 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this letter, terahertz (THz) pulse measurements with a chirped probe pulse are analyzed. The method of stationary phase is used to explore the relation between the temporal waveform of an input THz pulse and spectral distribution of an output probe pulse on a detector array. The dependence of the temporal resolution on the chirp rate, the spectrum of the chirped probe beam, and the spectral resolution of the spectrometer is discussed. We confirm that the temporal resolution of the chirped pulse technique is equal to the square root of the product of the original unchirped probe pulse duration and the chirped pulse duration. © 1998 American Institute of Physics.
Show PACS
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
42.62.Eh Metrological applications; optical frequency synthesizers for precision spectroscopy
42.60.Fc Modulation, tuning, and mode locking
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
42.79.Pw Imaging detectors and sensors

Directionally sensitive photorefractive interferometric line receiver for ultrasound detection on rough surfaces

Hemmo Tuovinen and Sridhar Krishnaswamy

Appl. Phys. Lett. 73, 2236 (1998); http://dx.doi.org/10.1063/1.121687 (3 pages) | Cited 4 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An adaptive heterodyne interferometer is configured as a line receiver using wave mixing in photorefractive bismuth silicate crystal. The line receiver is directionally most sensitive to ultrasound impinging normal to the line, and is significantly less sensitive to ultrasound impinging in other directions. Such a system is attractive in situations where the ultrasonic scatter from a specific direction is to be selectively pulled out in the presence of scatter from other “noise” sources. It is also demonstrated that the line probe system can be used to bridge the sensitivity gap that optical detection thus far has suffered vis-à-vis piezoelectric detection. © 1998 American Institute of Physics.
Show PACS
07.60.Ly Interferometers
42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials
42.70.Gi Light-sensitive materials
42.79.Jq Acousto-optical devices
43.38.Zp Acoustooptic and photoacoustic transducers
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing
42.65.Jx Beam trapping, self-focusing and defocusing; self-phase modulation
43.35.Zc Use of ultrasonics in nondestructive testing, industrial processes, and industrial products
81.70.Cv Nondestructive testing: ultrasonic testing, photoacoustic testing

Pinning of daisy modes in optically pumped vertical-cavity surface-emitting lasers

S. F. Pereira, M. B. Willemsen, M. P. van Exter, and J. P. Woerdman

Appl. Phys. Lett. 73, 2239 (1998); http://dx.doi.org/10.1063/1.121688 (3 pages) | Cited 9 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have observed stable single-mode oscillation of optically pumped vertical-cavity surface-emitting lasers (i.e., without fabricated aperture) in several high-order daisy modes. The surprising stability of the nodal lines of a daisy mode is explained as being due to the combined action of many microscopic defects; when a daisy mode is moved across the wafer, the effective correlation length of the orientation of the pinning is of the order of 1 μm. © 1998 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Laser action in GaN pyramids grown on (111) silicon by selective lateral overgrowth

S. Bidnyk, B. D. Little, Y. H. Cho, J. Krasinski, J. J. Song, W. Yang, and S. A. McPherson

Appl. Phys. Lett. 73, 2242 (1998); http://dx.doi.org/10.1063/1.121689 (3 pages) | Cited 33 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Laser action was observed in GaN pyramids under strong optical pumping at room temperature. The pyramids were laterally overgrown on a patterned GaN/AlN seeding layer grown on a (111) silicon substrate by metal–organic chemical vapor deposition. Each pyramid had a 15-μm-wide hexagonal base and was on average 15 μm in height. The pyramids were individually pumped, imaged, and spectrally analyzed through a high-magnification telescope system using a high-density pulsed excitation source. Under high levels of optical pumping, multimode laser at room temperature was observed. The integrated emission intensity for both spontaneous and lasing peaks was studied as a function of excitation power density. The effects of pyramid geometry and short-pulse excitation on the multimode nature of laser oscillations inside of the pyramids is discussed. This study suggests that GaN microstructures could potentially be used as pixel elements and high-density two-dimensional laser arrays. © 1998 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Linear and nonlinear optical properties of stepped InxGa1−xAs/GaAs quantum wells

N. Tomassini, A. D’Andrea, M. Righini, S. Selci, L. Calcagnile, R. Cingolani, D. Schiumarini, and M. G. Simeone

Appl. Phys. Lett. 73, 2245 (1998); http://dx.doi.org/10.1063/1.121690 (3 pages) | Cited 2 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Systematic studies of polaritons in single stepped quantum wells are performed, and the presence of forbidden transitions in optical spectra are taken as a fingerprint of nonhomogeneous indium concentration. The large intensities of such transitions for well thicknesses in the range of quasi-two-dimensional exciton behavior are pointed out. Finally, second harmonic generation excited at half gap is found to be enhanced with respect to the bulk contribution as suggested by the theory. © 1998 American Institute of Physics.
Show PACS
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
78.66.Fd III-V semiconductors
71.36.+c Polaritons (including photon-phonon and photon-magnon interactions)
71.35.Cc Intrinsic properties of excitons; optical absorption spectra

Dielectric properties of epitaxial BaTiO3 thin films

B. H. Hoerman, G. M. Ford, L. D. Kaufmann, and B. W. Wessels

Appl. Phys. Lett. 73, 2248 (1998); http://dx.doi.org/10.1063/1.121691 (3 pages) | Cited 32 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The dielectric response of epitaxial BaTiO3 thin films deposited on MgO was measured through surface electrodes as a function of applied bias, frequency, and temperature. The room temperature value of the dielectric constant was ∼500 with a dissipation factor, tan(δ), of 0.05 at 100 kHz. Measurements varying the bias field showed hysteresis of the dielectric response and a tunability of 30% for a maximum applied field of ∼7 MV/m. The frequency response of the dielectric constant is well described by a Curie–von Schweidler power law with an exponent ∼0.04 in the range 1 kHz–13 MHz. The films undergo a diffuse phase transition at temperatures higher than the bulk Curie temperature. The behavior of the dielectric response is attributed to the presence of residual strain in the epitaxial thin films. © 1998 American Institute of Physics.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.22.Ch Permittivity (dielectric function)
77.80.Dj Domain structure; hysteresis
77.80.B- Phase transitions and Curie point
77.55.-g Dielectric thin films

ZnSTe-based Schottky barrier ultraviolet detectors with nanosecond response time

Z. H. Ma, I. K. Sou, K. S. Wong, Z. Yang, and G. K. L. Wong

Appl. Phys. Lett. 73, 2251 (1998); http://dx.doi.org/10.1063/1.121692 (3 pages) | Cited 13 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
ZnSTe-based Schottky barrier photovoltaic detector arrays were fabricated on GaP(100) using a two-step molecular beam epitaxy growth approach. These detectors exhibit visible blind and ultraviolet (UV) sensitive response with a peak UV responsivity of 0.13 A/W and 1.2×106 V/W at 320 nm. The built-in potential of these detectors was determined to be 1.7 V. The temporal photocurrent response of a 400×400 μm2 detector was measured to be 1.2 ns, limited apparently by the resistance-capacitance (rc) constant of the detector structure. © 1998 American Institute of Physics.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
85.30.Hi Surface barrier, boundary, and point contact devices
85.30.Kk Junction diodes
81.05.Dz II-VI semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy

Emission process in bilayer organic light emitting diodes

C. Hochfilzer, G. Leising, Y. Gao, E. Forsythe, and C. W. Tang

Appl. Phys. Lett. 73, 2254 (1998); http://dx.doi.org/10.1063/1.121693 (3 pages) | Cited 8 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Efficient organic light emitting devices (OLEDs) using methyl substituted ladder-type poly (paraphenylene) (m-LPPP) and tris(8-hydroxy) quinoline aluminum (Alq3) as active materials are presented. For bilayer OLEDs the emissive region is found to be in both layers adjacent to the m-LPPP/Alq3 interface. The performance of these hybrid devices with constant m-LPPP thickness and varying Alq3 thickness is compared to that of a single layer m-LPPP device by investigating the relative spatial distribution of the light emission. The relation between the intensity of the light emitted from each layer and the distance to the cathode metal is discussed. Furthermore, the m-LPPP emission is also affected by the internal electric field at the interface. © 1998 American Institute of Physics.
Show PACS
85.60.Jb Light-emitting devices

Intracavity white-light continuum generation in a femtosecond Ti:sapphire oscillator

J.-P. Likforman, A. Alexandrou, and M. Joffre

Appl. Phys. Lett. 73, 2257 (1998); http://dx.doi.org/10.1063/1.121694 (3 pages) | Cited 1 time

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on intracavity white-light continuum generation in a Ti:sapphire oscillator at an average repetition rate of 200 kHz. A spectrally resolved pump-probe experiment is performed in order to demonstrate the potentialities of these continuum femtosecond pulses. © 1998 American Institute of Physics.
Show PACS
42.55.Rz Doped-insulator lasers and other solid state lasers
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
78.47.-p Spectroscopy of solid state dynamics
42.65.Re Ultrafast processes; optical pulse generation and pulse compression

Near-field scanning photoluminescence measurements using an uncoated fiber tip: A potential high resolution diagnostic technique for semiconductor devices

Ki-Bong Song, Ji-Eun Bae, Kyuman Cho, Sang-Youp Yim, and Seung-Han Park

Appl. Phys. Lett. 73, 2260 (1998); http://dx.doi.org/10.1063/1.121695 (3 pages) | Cited 5 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Near-field scanning optical microscopy, in which an uncoated fiber tip is used for delivering excitation light and picking up photoluminescence, is applied for diagnosing defects in semiconductor devices. Using this high resolution, potentially subdiffraction limited, and fast acquisition time scanning μ-photoluminescence (PL) technique, we are able to locate nonluminescing defects in a multiple quantum well grown by molecular beam epitaxy. Near-field characteristics of the measured spectral PL intensity are also discussed. © 1998 American Institute of Physics.
Show PACS
07.79.Fc Near-field scanning optical microscopes
07.60.Vg Fiber-optic instruments
07.60.Pb Conventional optical microscopes
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
78.66.Fd III-V semiconductors
61.72.-y Defects and impurities in crystals; microstructure
78.55.Cr III-V semiconductors

Strain compensated In1−xGaxAs(x<0.47) quantum well photodiodes for extended wavelength operation

J. Christopher Dries, Milind R. Gokhale, K. John Thomson, Stephen R. Forrest, and Robert Hull

Appl. Phys. Lett. 73, 2263 (1998); http://dx.doi.org/10.1063/1.121696 (3 pages) | Cited 12 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The use of highly strained (−2.0%) In0.83Ga0.17As quantum wells for the detection of light to a wavelength of λ∼2.0 μm is reported. Crystal quality for a 50 period multiple quantum well (MQW) detector grown on InP substrates is maintained through strain compensation using tensile strained In0.83Ga0.17P barriers. Transmission electron microscopy and double crystal x-ray diffraction reveal smooth interfaces and no observable defects for In0.83Ga0.17As layers with widths less than 80 Å. Single-pass quantum efficiencies of 30% have been achieved at λ=1.95 μm, using a 75 μm diam MQW, strain-compensated, top illuminated, low dark current (∼250 pA at 20 V) p-i-n detector. The theoretical cutoff wavelength limit for diodes fabricated using this technique is calculated to be λ=2.15 μm. © 1998 American Institute of Physics.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
85.60.Dw Photodiodes; phototransistors; photoresistors
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)

Surface-emitting, distributed-feedback diode lasers with uniform near-field intensity profile

James Lopez, Masoud Kasraian, and Dan Botez

Appl. Phys. Lett. 73, 2266 (1998); http://dx.doi.org/10.1063/1.121697 (3 pages) | Cited 2 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Theoretical analysis of second-order surface-emitting, complex-coupled distributed feedback diode lasers with first-order distributed Bragg reflectors (DBR) is presented. The DBR reflectors are shown to insure simultaneous operation in a virtually uniform near-field profile with high efficiency and adequate intermodal discrimination. Such devices display symmetric-mode (single-lobe) surface emission with relatively high external differential quantum efficiency (30%), low gain threshold (18 cm−1), and <8% near-field intensity profile variations (in the longitudinal direction). The devices have the potential to provide >100 mW of stable, single-mode cw power, significantly higher than it is possible with vertical-cavity surface-emitting lasers. It is also shown that the device studied here can be combined with a resonant optical waveguide array device to produce a 2D uniform near-field surface-emitting source capable of providing greater than 1 W cw power in a stable, single-lobed beam. © 1998 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)

Intensity and polarization switching behaviors of light emission induced with a scanning tunneling microscope

Zhanghua Wu, Tomonobu Nakayama, Shan Qiao, and Masakazu Aono

Appl. Phys. Lett. 73, 2269 (1998); http://dx.doi.org/10.1063/1.121698 (3 pages) | Cited 1 time

Full Text: Read Online (HTML) | Download PDF

Show Abstract
By applying voltage pulses across the tunnel junction, switching behaviors of the intensity and the polarization of light emission induced with a scanning tunneling microscope (STM) are observed. The STM images taken subsequently indicate that these switching behaviors are caused by a cluster with asymmetric shape on the nanometer scale being transferred between the sample and the tip by the pulse applied. Possible mechanisms for the switching behaviors are discussed. These observations could find applications in photonic devices on the nanometer scale. © 1998 American Institute of Physics.
Show PACS
07.79.Cz Scanning tunneling microscopes
78.60.Fi Electroluminescence
42.25.Ja Polarization
42.79.Ta Optical computers, logic elements, interconnects, switches; neural networks

Room-temperature formation of erbium-related luminescent centers in anodic alumina

S. K. Lazarouk, A. V. Mudryi, and V. E. Borisenko

Appl. Phys. Lett. 73, 2272 (1998); http://dx.doi.org/10.1063/1.121699 (3 pages) | Cited 12 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Luminescent Er-doped Al2O3 films have been fabricated at room temperature by a technique including magnetron deposition of Er-doped Al film on a silicon substrate and its subsequent electrochemical anodization. The films demonstrate strong Er-related photoluminescence at about 1.53 μm as recorded in the temperature range of 4.2–300 K. The effect is not influenced by annealing of the samples up to 200 °C. Upon annealing at 300–500 °C the luminescence intensity decreases, while above 600 °C it starts to recover. Annealing at 1000 °C restores the photoluminescence spectra to the initial level. The annealing peculiarities observed have been explained by dominant hydrogen outdiffusion at 300–500 °C, rearrangement of point defects at 600–800 °C, and recrystallization processes above 850 °C in the alumina film. Activation energies of these processes have been estimated to be 0.76 eV (for parabolic rate), 0.58 eV (for linear rate), and 0.46 eV (for linear rate), respectively. © 1998 American Institute of Physics.
Show PACS
78.66.Nk Insulators
78.55.Hx Other solid inorganic materials
71.55.Ht Other nonmetals
61.72.Cc Kinetics of defect formation and annealing
82.45.-h Electrochemistry and electrophoresis

Raman imaging of patterned silicon using a solid immersion lens

C. D. Poweleit, A. Gunther, S. Goodnick, and José Menéndez

Appl. Phys. Lett. 73, 2275 (1998); http://dx.doi.org/10.1063/1.121700 (3 pages) | Cited 21 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We show an enhanced spatial resolution using a solid immersion lens by directly imaging the Raman scattered light from silicon masked by periodic metal lines. A glass hemisphere solid immersion lens with an index of refraction n = 1.868 at 488 nm is used in conjunction with a 100×0.8 numerical aperture objective to obtain the enhanced spatial resolution. The increased numerical aperture is demonstrated by a direct line scan over the periodic metal lines. Compared with near-field optical microscopy, the solid immersion lens technique overcomes the difficulty of limited excitation power obtainable with tapered fibers, while providing excellent spatial resolution which in principle could be extended to the 0.1 μm range. © 1998 American Institute of Physics.
Show PACS
78.30.Am Elemental semiconductors and insulators
07.60.Rd Visible and ultraviolet spectrometers
42.79.Bh Lenses, prisms and mirrors
85.40.-e Microelectronics: LSI, VLSI, ULSI; integrated circuit fabrication technology
back to top
RSS Feeds

Visualization of 10 μm surface acoustic waves by stroboscopic x-ray topography

E. Zolotoyabko, D. Shilo, W. Sauer, E. Pernot, and J. Baruchel

Appl. Phys. Lett. 73, 2278 (1998); http://dx.doi.org/10.1063/1.121701 (3 pages) | Cited 13 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
X-ray topographs under acoustic wave excitation were taken from LiNbO3-based surface acoustic wave devices with He-implanted waveguide layers, using monochromatized synchrotron radiation from the European Synchrotron Radiation Facility (ESRF), Grenoble. Measurements were performed in the stroboscopic mode, i.e., by synchronizing the electron bunch frequency with the resonant frequency of the acoustic wave excitation in the 300 MHz range. These x-ray diffraction images showed plane acoustic wave propagation through the LiNbO3 crystals as well as a weak wavefront distortion due to the scattering on dislocation deformation fields. In some images secondary spherical waves were observed as a result of the strong acoustic wave interaction with the submicron size density perturbations. © 1998 American Institute of Physics.
Show PACS
77.65.Dq Acoustoelectric effects and surface acoustic waves (SAW) in piezoelectrics
43.35.Pt Surface waves in solids and liquids
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
back to top
RSS Feeds

Relaxor behavior and electromechanical properties of Pb(Mg1/3Nb2/3)O3 thin films

Z. Kighelman, D. Damjanovic, A. Seifert, L. Sagalowicz, and N. Setter

Appl. Phys. Lett. 73, 2281 (1998); http://dx.doi.org/10.1063/1.121702 (3 pages) | Cited 47 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Pb(Mg1/3Nb2/3)O3 (PMN) alkoxide precursor solutions were synthesized and used to prepare thin films by spin coating on TiO2/Pt/TiO2/SiO2/Si substrates. Many parameters like the use of homogeneous and stable precursor solutions and appropriate processing were used to greatly reduce the presence of the nonferroelectric pyrochlore phase. Transmission electron microscopy investigations, dielectric, electrostrictive, and direct current field induced piezoelectric measurements were carried out and have shown that PMN thin films exhibit a relaxor-like behavior. © 1998 American Institute of Physics.  
Show PACS
77.55.-g Dielectric thin films
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.80.-e Ferroelectricity and antiferroelectricity
77.65.Bn Piezoelectric and electrostrictive constants
77.22.Ch Permittivity (dielectric function)
81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
68.55.Nq Composition and phase identification

Formation of epitaxial CoSi2 spike in Co/Si3N4/Si(100) system and its crystallographic structure

Ji-Soo Park, Dong Kyun Sohn, Yeongcheol Kim, Jong-Uk Bae, Byung Hak Lee, Jeong Soo Byun, and Jae Jeong Kim

Appl. Phys. Lett. 73, 2284 (1998); http://dx.doi.org/10.1063/1.121703 (3 pages) | Cited 2 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The formation of CoSi2 spike in the Co/Si3N4/Si(100) system and its crystallographic structure have been investigated. An annealing at 1050 °C caused not only agglomeration of Co film but penetration of Co agglomerates through the Si3N4 layer. The CoSi2 spike of B type epitaxial and twinned orientation of CoSi2[110]∥Si[110], Si(11math)∥CoSi2(math1math) and Si(mathmath1)∥CoSi2(1math1) was formed in the Si substrate by the penetrated Co source. The formation of the epitaxial CoSi2 spike can be explained by the fast diffusion of Co atoms along defects in Si such as dislocations resulting from stress between the Si3N4 layer and the Si substrate. © 1998 American Institute of Physics.
Show PACS
68.35.Fx Diffusion; interface formation
61.72.Cc Kinetics of defect formation and annealing
66.30.Ny Chemical interdiffusion; diffusion barriers
68.55.-a Thin film structure and morphology
61.72.Hh Indirect evidence of dislocations and other defects (resistivity, slip, creep, strains, internal friction, EPR, NMR, etc.)
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)

Mono-sized single-wall carbon nanotubes formed in channels of AlPO4-5 single crystal

Z. K. Tang, H. D. Sun, J. Wang, J. Chen, and G. Li

Appl. Phys. Lett. 73, 2287 (1998); http://dx.doi.org/10.1063/1.121704 (3 pages) | Cited 84 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An alternative approach to the synthesis of mono-sized and parallel-aligned single-wall carbon nanotubes (SWCNs) is reported. The SWCNs are formed in 0.73 nm sized channels of microporous aluminophosphate crystallites by pyrolysis of tripropylamine molecules in the channels. They are characterized through transmission electron microscopy, polarized Raman scattering, and electrical transport measurements. Our results would open a door to further detailed studies on the intrinsic properties of carbon nanotubes now in progress. © 1998 American Institute of Physics.
Show PACS
61.46.-w Structure of nanoscale materials
78.30.Hv Other nonmetallic inorganics

Significantly enhanced creep resistance in low-melting-point solders through nanoscale oxide dispersions

H. Mavoori and S. Jin

Appl. Phys. Lett. 73, 2290 (1998); http://dx.doi.org/10.1063/1.121800 (3 pages) | Cited 10 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Nanosized, nonreacting, and noncoarsening oxide dispersoids have been incorporated into solder alloys to create an improved solder structure with an ultrafine grain size of ∼2000–5000 Å and significantly enhanced mechanical properties. As much as three orders of magnitude reduction in the steady-state creep rate has been achieved. These solders also exhibit improved (4–5 times higher) tensile strength at low strain rates and improved ductility under high strain rate deformation. It is demonstrated that with a dispersion of TiO2 particles, the Pb–Sn eutectic solder with a low melting point of 183 °C can be made more creep resistant than the 80Au–20Sn eutectic solder with a much higher melting point of 278 °C.
Show PACS
62.20.Hg Creep
81.40.Lm Deformation, plasticity, and creep
61.72.Hh Indirect evidence of dislocations and other defects (resistivity, slip, creep, strains, internal friction, EPR, NMR, etc.)
81.05.Ni Dispersion-, fiber-, and platelet-reinforced metal-based composites
82.70.-y Disperse systems; complex fluids
62.20.F- Deformation and plasticity
64.70.D- Solid-liquid transitions
61.46.-w Structure of nanoscale materials
81.07.-b Nanoscale materials and structures: fabrication and characterization

Fabrication of single-crystal lithium niobate films by crystal ion slicing

M. Levy, R. M. Osgood, R. Liu, L. E. Cross, G. S. Cargill, A. Kumar, and H. Bakhru

Appl. Phys. Lett. 73, 2293 (1998); http://dx.doi.org/10.1063/1.121801 (3 pages) | Cited 70 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the implementation of crystal ion slicing in lithium niobate (LiNbO3). Deep-ion implantation is used to create a buried sacrificial layer in single-crystal c-cut poled wafers of LiNbO3, inducing a large etch selectivity between the sacrificial layer and the rest of the sample. 9-μm-thick films of excellent quality are separated from the bulk and bonded to silicon and gallium arsenide substrates. These single-crystal films have the same room-temperature dielectric and pyroelectric characteristics, and ferroelectric transition temperature as single-crystal bulk. A stronger high-temperature pyroelectric response is found in the films. © 1998 American Institute of Physics.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.70.+a Pyroelectric and electrocaloric effects
77.22.Ch Permittivity (dielectric function)
77.80.B- Phase transitions and Curie point
77.55.-g Dielectric thin films
61.72.up Other materials
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
81.65.Cf Surface cleaning, etching, patterning
81.05.Je Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides)
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy

Picojoule and submillisecond calorimetry with micromechanical probes

Y. Nakagawa, R. Schäfer, and H.-J. Güntherodt

Appl. Phys. Lett. 73, 2296 (1998); http://dx.doi.org/10.1063/1.121802 (3 pages) | Cited 12 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The experimental limits of micromechanical calorimetry at ambient conditions are demonstrated. In the investigation of rotator phase transitions of n alkanes we have obtained a heat sensitivity of 500 pJ for a sample mass of about 7 pg with a time resolution of 0.5 ms. The time resolution is restricted by the thermal response of the bimetallic cantilever. A problem in the precise quantification of the transition enthalpies is heat transport through the atmospheric environment. A calibration of the apparatus constant is proposed to overcome this problem. © 1998 American Institute of Physics.
Show PACS
07.20.Fw Calorimeters
07.10.Cm Micromechanical devices and systems
61.50.-f Structure of bulk crystals
64.70.K- Solid-solid transitions
82.60.Fa Heat capacities and heats of phase transitions
06.20.F- Units and standards

Characteristics of high quality tantalum oxide films deposited by photoinduced chemical vapor deposition

Jun-Ying Zhang, Boon Lim, Ian W. Boyd, and Vincent Dusastre

Appl. Phys. Lett. 73, 2299 (1998); http://dx.doi.org/10.1063/1.121803 (3 pages) | Cited 21 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A method is presented for the photodeposition of tantalum oxide films from tantalum ethoxide and nitrous oxide using 172 nm radiation. The composition of the tantalum oxides deposited by this technique was determined by x-ray photoelectron spectroscopy while the optical and electrical properties were characterized using ellipsometry, capacitance–voltage, and current–voltage techniques. A leakage current density as low as 3.2×10−7 A cm−2 at a voltage of 10 V is obtained for the as-grown films. This is several orders of magnitude better than for any other Ta2O5 films deposited using either conventional or plasma-chemical vapor deposition techniques. © 1998 American Institute of Physics.
Show PACS
81.05.Je Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides)
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
82.80.Pv Electron spectroscopy (X-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.)
77.55.-g Dielectric thin films

Formation of CoTi barrier and increased thermal stability of CoSi2 film in Ti capped Co/Si(100) system

Dong Kyun Sohn, Ji-Soo Park, Byung Hak Lee, Jong-Uk Bae, Jeong Soo Byun, and Jae Jeong Kim

Appl. Phys. Lett. 73, 2302 (1998); http://dx.doi.org/10.1063/1.121804 (3 pages) | Cited 14 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We investigated the formation of CoSi2 for Ti capped Co on (100) Si substrate with emphasis on the Co–Ti interaction and its effect on thermal stability. A 15 nm thick Ti capping layer is shown to improve the interfacial roughness and thermal stability of CoSi2 film grown on Si substrate compared with TiN capping. The increased uniformity of silicide/Si(100) interface is speculated to result from retarded Co–Si reaction by the formation of CoTi binary phase. And the high thermal stability can be explained by the fact that the amount of Ti atoms in CoSi2 film for Ti capping is much higher than what is in TiN capping. It is likely that the surface Ti diffuses rapidly into CoSi2 grain boundaries and slows down the agglomeration process, thereby increasing thermal stability while Ti in TiN capping did not. © 1998 American Institute of Physics.
Show PACS
68.60.Dv Thermal stability; thermal effects
68.35.Fx Diffusion; interface formation
61.72.Mm Grain and twin boundaries
73.40.Ns Metal-nonmetal contacts
68.35.Ct Interface structure and roughness
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
back to top
RSS Feeds

Preferential growth of cubic GaN on sapphire (0001) substrates by metal organic molecular beam epitaxy

T. Kurobe, Y. Sekiguchi, J. Suda, M. Yoshimoto, and H. Matsunami

Appl. Phys. Lett. 73, 2305 (1998); http://dx.doi.org/10.1063/1.121805 (3 pages) | Cited 20 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Preferential growth of high-quality cubic GaN on sapphire (0001) substrates was realized at 800 °C under a Ga-rich condition by metal organic molecular beam epitaxy. Hexagonal GaN was grown under a N-rich condition. On the contrary, under the Ga-rich condition, the growing layer changed from a hexagonal phase to a cubic phase as the growth proceeds, which was verified by in situ reflection high-energy electron diffraction. The low-temperature photoluminescence (PL) of this layer was dominated by a sharp and intense excitonic emission of cubic GaN, indicating high crystal quality. The results of PL and x-ray diffraction indicate that the polytype of GaN can be intentionally controlled by changing V/III ratios without serious degradation of crystal quality. In addition, enhancement of cubic phase growth by using a low-temperature grown buffer layer is also discussed. © 1998 American Institute of Physics.
Show PACS
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.-a Thin film structure and morphology
81.05.Ea III-V semiconductors
78.55.Cr III-V semiconductors
78.66.Fd III-V semiconductors
61.50.Ks Crystallographic aspects of phase transformations; pressure effects
61.66.Fn Inorganic compounds
Page 1 of 3 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close