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

26 Oct 1998

Volume 73, Issue 17, pp. 2393-2529

Page 2 of 2 Pages Previous Page | Jump to Page
back to top
RSS Feeds

Transport properties of two-dimensional electron gases containing InAs self-assembled dots

G. H. Kim, D. A. Ritchie, M. Pepper, G. D. Lian, J. Yuan, and L. M. Brown

Appl. Phys. Lett. 73, 2468 (1998); http://dx.doi.org/10.1063/1.122484 (3 pages) | Cited 22 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present a study of the transport properties of two-dimensional electron gases formed in GaAs/AlGaAs heterostructures in which InAs self-assembled quantum dots have been inserted in the center of a GaAs quantum well. We observed that, while maintaining a constant carrier density, the mobility increased as the InAs dot density was reduced. The ratio of the transport to the quantum lifetime was measured to be approximately five with the dominant scattering mechanism attributed to short-range scattering from the inserted InAs dots. © 1998 American Institute of Physics.
Show PACS
73.61.Ey III-V semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)

Fermi-edge singularity observed in a modulation-doped AlGaN/GaN heterostructure

Jian-Ping Zhang, Dian-Zhao Sun, Xiao-Liang Wang, Mei-Ying Kong, Yi-Ping Zeng, Jin-Min Li, and Lan-Ying Lin

Appl. Phys. Lett. 73, 2471 (1998); http://dx.doi.org/10.1063/1.122485 (2 pages) | Cited 7 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this letter, we report on the observation of Fermi-edge singularity in a modulation-doped AlGaN/GaN heterostructure grown on a c-face sapphire substrate by NH3 source molecular beam epitaxy. The two-dimensional electron gas (2DEG) characteristic of the structure is manifested by variable temperature Hall effect measurements down to 7 K. Low-temperature photoluminescence (PL) spectra show a broad emission band originating from the recombination of the 2DEG and localized holes. The enhancement in PL intensity in the high-energy side approaching Fermi level was observed at temperatures below 20 K. At higher temperatures, the enhancement disappears because of the thermal broadening of the Fermi edge. © 1998 American Institute of Physics.
Show PACS
73.20.At Surface states, band structure, electron density of states
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
78.55.Cr III-V semiconductors
78.66.Fd III-V semiconductors
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
71.18.+y Fermi surface: calculations and measurements; effective mass, g factor

Nitrogenated tetrahedral amorphous carbon films prepared by ion-beam-assisted filtered cathodic vacuum arc technique for solar cells application

L. K. Cheah, X. Shi, E. Liu, and J. R. Shi

Appl. Phys. Lett. 73, 2473 (1998); http://dx.doi.org/10.1063/1.122486 (3 pages) | Cited 18 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Fabrication and characterization of nitrogenated tetrahedral amorphous carbon (ta-C:N) semiconductor/crystalline p-type silicon (p-Si) heterojunction structures are reported. The electron-hole pairs generated from both ta-C:N and Si depletion regions were observed from photoresponse measurements. The peaks are centered at about 540 and 1020 nm, which correspond to the optical absorption edge of ta-C:N and p-Si, respectively. The reverse current increased by three orders of magnitude when the structures were exposed to AM1 light. A photovoltaic effect was observed from ta-C:N and the values of short circuit current, open circuit voltage, and field factor obtained are 5.05 mA cm−2, 270 mV, and 0.2631, respectively. © 1998 American Institute of Physics.
Show PACS
84.60.Jt Photoelectric conversion
81.05.Gc Amorphous semiconductors
81.05.Cy Elemental semiconductors
73.61.Jc Amorphous semiconductors; glasses
78.66.Jg Amorphous semiconductors; glasses
73.40.Lq Other semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
81.15.Jj Ion and electron beam-assisted deposition; ion plating
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
73.50.Pz Photoconduction and photovoltaic effects
78.40.Fy Semiconductors
73.61.Cw Elemental semiconductors

Plasma heating in highly excited GaN/AlGaN multiple quantum wells

K. C. Zeng, R. Mair, J. Y. Lin, H. X. Jiang, W. W. Chow, A. Botchkarev, and H. Morkoç

Appl. Phys. Lett. 73, 2476 (1998); http://dx.doi.org/10.1063/1.122487 (3 pages) | Cited 9 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Time-resolved photoluminescence (PL) spectroscopy was used to investigate carrier distributions in a GaN/AlGaN multiple quantum well (MQW) sample under high excitation intensities necessary to achieve lasing threshold. Room temperature PL spectra showed optical transitions involving both confined and unconfined states in the quantum well structure. Analysis of the experimental results using a microscopic theory, indicates that at high excitation the carrier distributions are characterized by plasma temperatures which are significantly higher than the lattice temperature. The implications of our findings on GaN MQW laser design are also discussed. © 1998 American Institute of Physics.
Show PACS
73.50.Mx High-frequency effects; plasma effects
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
73.61.Ey III-V semiconductors
78.66.Fd III-V semiconductors
78.55.Cr III-V semiconductors
42.55.Px Semiconductor lasers; laser diodes
78.47.-p Spectroscopy of solid state dynamics
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)

Selective formation of one- and two-dimensional arrayed InGaAs quantum dots using Ga2O3 thin film as a mask material

Cheol Koo Hahn, Young Ju Park, Eun Kyu Kim, Suk-Ki Min, Suk Koo Jung, and Jung Ho Park

Appl. Phys. Lett. 73, 2479 (1998); http://dx.doi.org/10.1063/1.122488 (3 pages) | Cited 15 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the selective formation of InGaAs quantum dots (QDs) by molecular beam epitaxy. Nanoscale patterned Ga2O3 thin film deposited on the GaAs (100) substrate was employed as a mask material. Due to the enhanced migration effect of the group-III adatoms, such as Ga and In on Ga2O3 mask layer, the InGaAs QDs formed on the patterned substrate results in coalesced islands unlike those formed on the nonpatterned substrate. The estimation of the relative volume of the islands per unit area revealed that the desorption process as well as the migration of the Ga and In adatoms might occur on the Ga2O3 layer during the growth process, providing a good selective growth of self-assembled QDs. © 1998 American Institute of Physics.
Show PACS
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
68.55.-a Thin film structure and morphology
81.05.Ea III-V semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
68.03.Fg Evaporation and condensation of liquids
68.43.Mn Adsorption kinetics
68.35.Fx Diffusion; interface formation
85.40.Hp Lithography, masks and pattern transfer

Characterization of heavily carbon-doped InGaAsP layers grown by chemical beam epitaxy using tetrabromide

Hideo Sugiura, Manabu Mitsuhara, and Susumu Kondo

Appl. Phys. Lett. 73, 2482 (1998); http://dx.doi.org/10.1063/1.122489 (3 pages) | Cited 2 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Carbon doping in InGaAsP films using tetrabromide (CBr4) in chemical beam epitaxy has been studied, focusing on the relationship between the composition and the carrier concentration. The films with an equivalent wavelength of more than 1.4 μm have p-type conduction while the films with less than 1.3 μm have n-type conduction. Specifically, the hole concentration decreases from 7×1019 to 7×1018 cm−3 with decreasing wavelength in the 1.4–1.66 μm range, while electron concentration increases from 5×1018 to 2×1019 cm−3 with decreasing wavelength in the 1.1–1.3 μm range. Secondary-ion mass spectroscopy reveals that the incorporated carbon atom concentration is the same between an InGaAs film and a 1.4 μm equivalent wavelength InGaAsP film under a fixed CBr4 flux. Increase in gallium mole fraction monotonously increases hole concentrations under a fixed group-V mole fraction. We have found that the In1−xGaxAs1−yPy conduction type is mainly determined by two parameters: the Ga and P mole fractions, i.e., p type if x>y. © 1998 American Institute of Physics.
Show PACS
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
81.05.Ea III-V semiconductors
61.72.uj III-V and II-VI semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
73.61.Ey III-V semiconductors
72.80.Ey III-V and II-VI semiconductors
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths
68.55.Nq Composition and phase identification

Multisubband hot-electron transport in GaN-based quantum wells

N. A. Zakhleniuk, C. R. Bennett, B. K. Ridley, and M. Babiker

Appl. Phys. Lett. 73, 2485 (1998); http://dx.doi.org/10.1063/1.122490 (3 pages) | Cited 8 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A simple rigorous analytical theory of two-dimensional (2D) nonequilibrium electrons occupying an arbitrary number of subbands in a quantum well is developed. The electric-field dependence of electron mobility and the average kinetic energy for AlN/GaN quantum wells are presented. At temperatures below 200 K the electron mobility is controlled mainly by the acoustic phonon scattering and it is a nonmonotonous function of the electric field, which has a maximum. At room and higher temperatures the interaction with both acoustic and polar optical phonons determine the hot-electron mobility and it depends very weakly on the electric field. Both the mobility and average energy of 2D electrons are smaller than that for three-dimensional (3D) electrons in the bulk semiconductor. Our theory provides a self-consistent transition from the 2D to the 3D regime of electron transport with increasing electric field accompanied by the occupation of an increasingly large number of subbands by the electrons. © 1998 American Institute of Physics.
Show PACS
73.61.Ga II-VI semiconductors
73.50.Fq High-field and nonlinear effects
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
63.20.K- Phonon interactions
71.38.-k Polarons and electron-phonon interactions

Competition of shot noise and hot-electron noise in GaAs planar-doped barrier diode

V. Gružinskis, J. Liberis, A. Matulionis, P. Sakalas, E. Starikov, P. Shiktorov, B. Szentpáli, V. Van Tuyen, and H. L. Hartnagel

Appl. Phys. Lett. 73, 2488 (1998); http://dx.doi.org/10.1063/1.122491 (3 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Microwave noise in GaAs planar-doped barrier diodes is investigated over a wide range of bias. Suppression of shot noise at intermediate densities of current and an onset of hot-electron noise at high densities are evidenced by experimental data and Monte Carlo simulation. © 1998 American Institute of Physics.  
Show PACS
85.30.Kk Junction diodes
84.40.-x Radiowave and microwave (including millimeter wave) technology
85.30.De Semiconductor-device characterization, design, and modeling
73.50.Td Noise processes and phenomena
02.70.Rr General statistical methods
73.61.Ey III-V semiconductors
back to top
RSS Feeds

Microwave near-field imaging of electric fields in a superconducting microstrip resonator

Ashfaq S. Thanawalla, S. K. Dutta, C. P. Vlahacos, D. E. Steinhauer, B. J. Feenstra, Steven M. Anlage, F. C. Wellstood, and Robert B. Hammond

Appl. Phys. Lett. 73, 2491 (1998); http://dx.doi.org/10.1063/1.122492 (3 pages) | Cited 10 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We describe the use of a cryogenic near-field scanning microwave microscope to image microwave electric fields from superconducting and normal-metal microstrip resonators. The microscope employs an open-ended coaxial probe and operates from 77 to 300 K in the 0.01–20 GHz frequency range with a spatial resolution of about 200 μm. We describe the operation of the system and present microwave images of Cu and Tl2Ba2CaCu2O8 microstrip resonators, showing standing wave patterns at the fundamental and second harmonic frequencies. © 1998 American Institute of Physics.
Show PACS
07.57.-c Infrared, submillimeter wave, microwave and radiowave instruments and equipment
85.25.Pb Superconducting infrared, submillimeter and millimeter wave detectors
84.40.Az Waveguides, transmission lines, striplines
84.37.+q Measurements in electric variables (including voltage, current, resistance, capacitance, inductance, impedance, and admittance, etc.)
07.20.Mc Cryogenics; refrigerators, low-temperature detectors, and other low-temperature equipment
74.72.-h Cuprate superconductors

Magnetic field dependence of quasiparticle losses in a superconductor

J. N. Ullom, P. A. Fisher, and M. Nahum

Appl. Phys. Lett. 73, 2494 (1998); http://dx.doi.org/10.1063/1.122493 (3 pages) | Cited 7 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have studied the propagation of quasiparticles in a superconducting film which is penetrated by a magnetic field. We inject quasiparticles into an Al film at 75 mK using a normal–insulator–superconductor tunnel junction and measure the flux of quasiparticles which diffuse into an adjoining thermal detector. A magnetic field applied perpendicular to the plane of the film produces regions of reduced energy gap which trap quasiparticles. We find a significant reduction in the quasiparticle flux for fields as small as 2 G and explain our measurements with a model that incorporates inelastic scattering rates in Al and the characteristics of field penetration. © 1998 American Institute of Physics.
Show PACS
74.78.-w Superconducting films and low-dimensional structures
74.45.+c Proximity effects; Andreev reflection; SN and SNS junctions
85.25.-j Superconducting devices
back to top
RSS Feeds

Atomically defined epitaxy and physical properties of strained La0.6Sr0.4MnO3 films

M. Izumi, Y. Konishi, T. Nishihara, S. Hayashi, M. Shinohara, M. Kawasaki, and Y. Tokura

Appl. Phys. Lett. 73, 2497 (1998); http://dx.doi.org/10.1063/1.122494 (3 pages) | Cited 76 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
La0.6Sr0.4MnO3 thin films were fabricated on SrTiO3 (001) substrates using pulsed laser deposition with observing persistent intensity oscillation of reflection high-energy electron diffraction. By atomic force microscopy, the surface of resulting films was confirmed to be extremely flat, showing atomically smooth terraces and 0.4 nm high steps corresponding to a unit cell height of perovskite. The surface terminating atomic layer was unambiguously assigned to the MnO2 layer by coaxial impact collision ion scattering spectroscopy. Crystal symmetry of the films is distorted into a tetragonal one due to the strain to fulfill perfect in-plane matching with the substrate even for films as thick as 100 nm. Even for films as thin as 4 nm (10 unit cells), ferromagnetic transition takes place to induce a metallic state and large negative magnetoresistance is observed as well. © 1998 American Institute of Physics.
Show PACS
68.55.-a Thin film structure and morphology
81.05.Je Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides)
81.15.Fg Pulsed laser ablation deposition
81.15.Kk Vapor phase epitaxy; growth from vapor phase
73.61.At Metal and metallic alloys
68.35.B- Structure of clean surfaces (and surface reconstruction)
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces
75.50.Cc Other ferromagnetic metals and alloys
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)
75.70.Ak Magnetic properties of monolayers and thin films
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
72.60.+g Mixed conductivity and conductivity transitions

On the synthesis and magnetic properties of Nd(Fe,Mo,Ti)12

Q. M. Cheng, J. H. Lin, and M. Z. Su

Appl. Phys. Lett. 73, 2500 (1998); http://dx.doi.org/10.1063/1.122495 (3 pages) | Cited 1 time

Full Text: Read Online (HTML) | Download PDF

Show Abstract
NdFe10+xMo2−2xTix and NdFe10+xMo2−x (0 ⩽ x ⩽ 1.0) have been synthesized by using a reduction-diffusion process with superfine precursor particles as starting materials. The easy direction of magnetization of the NdFe10+xMo2−2xTix system has been determined by ac susceptibility and x-ray diffraction of the aligned samples. By comparison with NdFe12+xMo2−x, a magnetic phase diagram of the NdFe10+xMo2−2xTix system has been proposed. © 1998 American Institute of Physics.
Show PACS
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
75.30.Cr Saturation moments and magnetic susceptibilities
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)
61.66.Dk Alloys
81.05.Bx Metals, semimetals, and alloys
75.40.-s Critical-point effects, specific heats, short-range order

Easy axis distribution in interacting fine-particle systems

R. Iglesias, H. Rubio, and S. Suárez

Appl. Phys. Lett. 73, 2503 (1998); http://dx.doi.org/10.1063/1.122496 (3 pages) | Cited 6 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A general method applicable to interacting fine-particle systems in the mean-field approximation is developed. When the external applied field is decreased, interaction and disorder give rise to a rotation of the integration domain that must be considered for the determination of the average values. This model provides useful expressions for obtaining the magnetic easy axis distribution, and reproducing the results of the preceding noninteracting theories when interaction between particles is not taken into account. © 1998 American Institute of Physics.
Show PACS
75.50.Tt Fine-particle systems; nanocrystalline materials
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
75.30.Gw Magnetic anisotropy

Tunneling-like magnetoresistance in bicrystal La0.8Sr0.2MnO3−δ thin films

K. Steenbeck, T. Eick, K. Kirsch, H.-G. Schmidt, and E. Steinbeiß

Appl. Phys. Lett. 73, 2506 (1998); http://dx.doi.org/10.1063/1.122497 (3 pages) | Cited 51 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Epitaxial ferromagnetic La0.8Sr0.2MnO3−δ films have been sputtered on SrTiO3 bicrystal substrates. Etched patterns crossing the bicrystal grain boundary are compared with identical patterns not crossing it. The films were annealed at different conditions and their magnetoresistance measured as a function of temperature T and of in plane magnetic field H strength and direction. Annealing at 900 °C was found to modify the grain boundary and to increase its magnetoresistance. For H = ±80 Oe parallel to the grain boundary and T = 32 K narrow magnetoresistance peaks of 60% height are measured. They are interpreted in the frame of an in plane magnetotunneling structure. © 1998 American Institute of Physics.
Show PACS
75.47.De Giant magnetoresistance
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
73.61.At Metal and metallic alloys
75.50.Dd Nonmetallic ferromagnetic materials
72.15.Gd Galvanomagnetic and other magnetotransport effects
73.40.Gk Tunneling
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
61.72.Mm Grain and twin boundaries
75.60.Nt Magnetic annealing and temperature-hysteresis effects

Forced magnetostriction in FeZr-based amorphous alloys

J. Arcas, A. Hernando, J. M Barandiarán, M. Schwetz, and R. Grössinger

Appl. Phys. Lett. 73, 2509 (1998); http://dx.doi.org/10.1063/1.122498 (3 pages) | Cited 4 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The magnetostriction constant and forced volume expansion have been measured in amorphous melt–spun ribbons of composition Fe88Zr7B4Cu1, Fe87.2Zr7.4B4.3Cu1.1, Fe86Zr7B6Cu1, and Fe85Zr7B6Cu2. The values obtained show that the volume expansion plays the most important role at room temperature. The magnetic character of these samples was also estimated from the Arrott plots at room temperature and from the thermal dependence of the magnetization. As has been found, the volume contribution decreases with the Curie temperature, whereas the saturation magnetostriction contribution increases. The results measured are also related with the previously reported stress dependence of the Curie temperature. © 1998 American Institute of Physics.
Show PACS
75.50.Kj Amorphous and quasicrystalline magnetic materials
75.50.Bb Fe and its alloys
75.80.+q Magnetomechanical effects, magnetostriction
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
81.05.Kf Glasses (including metallic glasses)

Site occupancy of Zr in Nd(FeZr)B magnet during hydrogenation disproportionation desorption recombination process

A. Ashfaq, M. Matsuura, and M. Sakurai

Appl. Phys. Lett. 73, 2512 (1998); http://dx.doi.org/10.1063/1.122499 (3 pages) | Cited 7 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In order to elucidate the role of Zr addition for the evolution of magnetic anisotropy in hydrogenation disproportionation desorption recombination treated NdFeB magnets, Zr site occupancy in Nd16Fe75.5Zr0.5B8 alloy has been investigated by means of x-ray absorption fine structure. Zr is found to occupy preferably the Fe(j2) sites in the Nd2Fe14B structure for the as-cast state and keeps this position in the disproportionated stage. Zr(j2) sites are situated at the position connecting two Fe-hexagonal nets where strong Fe–Zr bondings stabilize Nd2Fe14B structure against disproportionation. © 1998 American Institute of Physics.
Show PACS
75.50.Ww Permanent magnets
75.50.Bb Fe and its alloys
75.30.Gw Magnetic anisotropy
68.03.Fg Evaporation and condensation of liquids
68.43.Mn Adsorption kinetics
61.05.cj X-ray absorption spectroscopy: EXAFS, NEXAFS, XANES, etc.
78.70.Dm X-ray absorption spectra
61.50.Lt Crystal binding; cohesive energy
75.50.Vv High coercivity materials
back to top
RSS Feeds

Operation of logic function in a Coulomb blockade device

K. Tsukagoshi, B. W. Alphenaar, and K. Nakazato

Appl. Phys. Lett. 73, 2515 (1998); http://dx.doi.org/10.1063/1.122500 (3 pages) | Cited 15 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This letter presents the experimental demonstration of a Coulomb blockade (CB) logic device. Our logic architecture consists of an array of current pathways, controlled by CB switching nodes. In this architecture, high gain is not required to transmit information, making it well suited to the CB device. Each CB node is switched between a blockaded state and a completely pinched-off state, minimizing the influence of stray potentials. Using a multi-phase clocking scheme to precisely control electron flow, the AND logic function is observed using as few as 160 electrons. © 1998 American Institute of Physics.
Show PACS
85.35.Ds Quantum interference devices
73.23.Hk Coulomb blockade; single-electron tunneling
84.30.Sk Pulse and digital circuits

Nonferroelectric epitaxial Sr–Bi–Ta oxide thin film with a high dielectric constant

S. J. Hyun, B. H. Park, S. D. Bu, J. H. Jung, and T. W. Noh

Appl. Phys. Lett. 73, 2518 (1998); http://dx.doi.org/10.1063/1.122501 (3 pages) | Cited 16 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Two kinds of epitaxial Sr–Bi–Ta oxides were grown on La0.5Sr0.5CoO3(001)/LaAlO3(001) substrates by pulsed laser deposition. At a temperature higher than 650 °C, c-axis oriented SrBi2Ta2O9 films could be deposited epitaxially. At 550 °C, an epitaxial film with a cubic fluorite-like phase could be grown. Although the film with the cubic phase does not show ferroelectric properties, it has good electrical properties which are suitable for high capacitance applications. © 1998 American Institute of Physics.
Show PACS
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
77.55.-g Dielectric thin films
77.22.Ch Permittivity (dielectric function)
81.15.Kk Vapor phase epitaxy; growth from vapor phase
81.15.Fg Pulsed laser ablation deposition
81.05.Je Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides)
68.55.-a Thin film structure and morphology
77.22.Gm Dielectric loss and relaxation

Laser-induced thermal expansion of a scanning tunneling microscope tip measured with an atomic force microscope cantilever

R. Huber, M. Koch, and J. Feldmann

Appl. Phys. Lett. 73, 2521 (1998); http://dx.doi.org/10.1063/1.122502 (3 pages) | Cited 22 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We investigate the transient thermal expansion of a scanning tunneling microscope tip after excitation with intense femtosecond laser pulses. The expansion dynamics are measured electrically by monitoring the time-resolved tunneling current and mechanically by use of an atomic force microscope. The tip expansion reaches values as high as 15 nm and exceeds the typical working distance of a scanning tunneling microscope by far. This results in a mechanical contact between tunneling tip and surface leading to surface modifications on a nanometer scale. Our findings clarify the mechanism of the recently proposed focusing of laser radiation in the near field of a tip technique [J. Jersch and K. Dickmann, Appl. Phys. Lett. 68, 868 (1996)] for nanostructuring. © 1998 American Institute of Physics.
Show PACS
68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)
68.37.Ps Atomic force microscopy (AFM)
68.37.Rt Magnetic force microscopy (MFM)
68.37.Uv Near-field scanning microscopy and spectroscopy
07.79.Cz Scanning tunneling microscopes
07.79.Lh Atomic force microscopes
68.35.B- Structure of clean surfaces (and surface reconstruction)
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
65.40.De Thermal expansion; thermomechanical effects

Electrical field impact on the gas adsorptivity of thin metal oxide films

M. Bögner, A. Fuchs, K. Scharnagl, R. Winter, T. Doll, and I. Eisele

Appl. Phys. Lett. 73, 2524 (1998); http://dx.doi.org/10.1063/1.122503 (3 pages) | Cited 11 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A thin semiconducting NiO film is exposed to NO2 at room temperature. This exposure causes a work function change at the surface of the film due to adsorption of the NO2 molecules. It is found that there is a strong dependence of the adsorptivity, i.e., the amount of work function change per unit time, on the magnitude of an electrical field that is applied perpendicular to the film surface. This induced adsorptivity change is known as the electroadsorptive effect. In order to modulate the adsorptivity significantly, the electrical field strength must exceed 104 V/cm. This requirement can be achieved by using hybrid suspended gate field effect transistors with an air gap height below 1 μm. © 1998 American Institute of Physics.
Show PACS
68.03.Fg Evaporation and condensation of liquids
68.43.Mn Adsorption kinetics
73.30.+y Surface double layers, Schottky barriers, and work functions

Noncontact nanolithography using the atomic force microscope

Kathryn Wilder, Calvin F. Quate, Dennis Adderton, Robert Bernstein, and Virgil Elings

Appl. Phys. Lett. 73, 2527 (1998); http://dx.doi.org/10.1063/1.122504 (3 pages) | Cited 53 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have demonstrated that the atomic force microscope (AFM) operating in air may be used to pattern narrow features in resist in a noncontact lithography mode. A micromachined AFM cantilever with an integrated silicon probe tip acts as a source of electrons. The field emission current from the tip is sensitive to the tip-to-sample spacing and is used as the feedback signal to control this spacing. Feature sizes below 30 nm have been patterned in 65-nm-thick resist and transferred through reactive ion etching into the silicon substrate. We show that the same AFM probe used for noncontact patterning can be used to image the sample. In addition to eliminating the problem of tip wear, this noncontact system is easily adapted to multiple-tip arrays where each cantilever has an integrated actuator to adjust the probe height. © 1998 American Institute of Physics.
Show PACS
81.07.-b Nanoscale materials and structures: fabrication and characterization
81.16.-c Methods of micro- and nanofabrication and processing
85.35.-p Nanoelectronic devices
85.40.Hp Lithography, masks and pattern transfer
68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)
68.37.Ps Atomic force microscopy (AFM)
68.37.Rt Magnetic force microscopy (MFM)
68.37.Uv Near-field scanning microscopy and spectroscopy
81.65.Cf Surface cleaning, etching, patterning
07.79.Lh Atomic force microscopes
Page 2 of 2 Pages Previous Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close